Don't require test wrappers to preserve environment variables, use more consistent environment.

One wart in the original support for test wrappers for cross testing,
as noted in
<https://sourceware.org/ml/libc-alpha/2012-10/msg00722.html>, is the
requirement for test wrappers to pass a poorly-defined set of
environment variables from the build system to the system running the
glibc under test.  Although some variables are passed explicitly via
$(test-wrapper-env), including LD_* variables that simply can't be
passed implicitly because of the side effects they'd have on the build
system's dynamic linker, others are passed implicitly, including
variables such as GCONV_PATH and LOCPATH that could potentially affect
the build system's libc (so effectively relying on any such effects
not breaking the wrappers).  In addition, the code in
cross-test-ssh.sh for preserving environment variables is fragile (it
depends on how bash formats a list of exported variables, and could
well break for multi-line variable definitions where the contents
contain things looking like other variable definitions).

This patch moves to explicitly passing environment variables via
$(test-wrapper-env).  Makefile variables that previously used
$(test-wrapper) are split up into -before-env and -after-env parts
that can be passed separately to the various .sh files used in
testing, so those files can then insert environment settings between
the two parts.

The common default environment settings in make-test-out are made into
a separate makefile variable that can also be passed to scripts,
rather than many scripts duplicating those settings (for testing an
installed glibc, it is desirable to have the GCONV_PATH setting on
just one place, so just that one place needs to support it pointing to
an installed sysroot instead of the build tree).  The default settings
are included in the variables such as $(test-program-prefix), so that
if tests do not need any non-default settings they can continue to use
single variables rather than the split-up variables.

Although this patch cleans up LC_ALL=C settings (that being part of
the common defaults), various LANG=C and LANGUAGE=C settings remain.
Those are generally unnecessary and I propose a subsequent cleanup to
remove them.  LC_ALL takes precedence over LANG, and while LANGUAGE
takes precedence over LC_ALL, it only does so for settings other than
LC_ALL=C.  So LC_ALL=C on its own is sufficient to ensure the C
locale, and anything that gets LC_ALL=C does not need the other
settings.

While preparing this patch I noticed some tests with .sh files that
appeared to do nothing beyond what the generic makefile support for
tests can do (localedata/tst-wctype.sh - the makefiles support -ENV
variables and .input files - and localedata/tst-mbswcs.sh - just runs
five tests that could be run individually from the makefile).  So I
propose another subsequent cleanup to move those to using the generic
support instead of special .sh files.

Tested x86_64 (native) and powerpc32 (cross).

	* Makeconfig (run-program-env): New variable.
	(run-program-prefix-before-env): Likewise.
	(run-program-prefix-after-env): Likewise.
	(run-program-prefix): Define in terms of new variables.
	(built-program-cmd-before-env): New variable.
	(built-program-cmd-after-env): Likewise.
	(built-program-cmd): Define in terms of new variables.
	(test-program-prefix-before-env): New variable.
	(test-program-prefix-after-env): Likewise.
	(test-program-prefix): Define in terms of new variables.
	(test-program-cmd-before-env): New variable.
	(test-program-cmd-after-env): Likewise.
	(test-program-cmd): Define in terms of new variables.
	* Rules (make-test-out): Use $(run-program-env).
	* scripts/cross-test-ssh.sh (env_blacklist): Remove variable.
	(help): Do not mention environment variables.  Mention
	--timeoutfactor option.
	(timeoutfactor): New variable.
	(blacklist_exports): Remove function.
	(exports): Remove variable.
	(command): Do not include ${exports}.
	* manual/install.texi (Configuring and compiling): Do not mention
	test wrappers preserving environment variables.  Mention that last
	assignment to a variable must take precedence.
	* INSTALL: Regenerated.
	* benchtests/Makefile (run-bench): Use $(run-program-env).
	* catgets/Makefile ($(objpfx)test1.cat): Use
	$(built-program-cmd-before-env), $(run-program-env) and
	$(built-program-cmd-after-env).
	($(objpfx)test2.cat): Do not specify environment variables
	explicitly.
	($(objpfx)de/libc.cat): Use $(built-program-cmd-before-env),
	$(run-program-env) and $(built-program-cmd-after-env).
	($(objpfx)test-gencat.out): Use $(test-program-cmd-before-env),
	$(run-program-env) and $(test-program-cmd-after-env).
	($(objpfx)sample.SJIS.cat): Do not specify environment variables
	explicitly.
	* catgets/test-gencat.sh: Use test_program_cmd_before_env,
	run_program_env and test_program_cmd_after_env arguments.
	* elf/Makefile ($(objpfx)tst-pathopt.out): Use $(run-program-env).
	* elf/tst-pathopt.sh: Use run_program_env argument.
	* iconvdata/Makefile ($(objpfx)iconv-test.out): Use
	$(test-wrapper-env) and $(run-program-env).
	* iconvdata/run-iconv-test.sh: Use test_wrapper_env and
	run_program_env arguments.
	* iconvdata/tst-table.sh: Do not set GCONV_PATH explicitly.
	* intl/Makefile ($(objpfx)tst-gettext.out): Use
	$(test-program-prefix-before-env), $(run-program-env) and
	$(test-program-prefix-after-env).
	($(objpfx)tst-gettext2.out): Likewise.
	* intl/tst-gettext.sh: Use test_program_prefix_before_env,
	run_program_env and test_program_prefix_after_env arguments.
	* intl/tst-gettext2.sh: Likewise.
	* intl/tst-gettext4.sh: Do not set environment variables
	explicitly.
	* intl/tst-gettext6.sh: Likewise.
	* intl/tst-translit.sh: Likewise.
	* malloc/Makefile ($(objpfx)tst-mtrace.out): Use
	$(test-program-prefix-before-env), $(run-program-env) and
	$(test-program-prefix-after-env).
	* malloc/tst-mtrace.sh: Use test_program_prefix_before_env,
	run_program_env and test_program_prefix_after_env arguments.
	* math/Makefile (run-regen-ulps): Use $(run-program-env).
	* nptl/Makefile ($(objpfx)tst-tls6.out): Use $(run-program-env).
	* nptl/tst-tls6.sh: Use run_program_env argument.  Set LANG=C
	explicitly with each use of ${test_wrapper_env}.
	* posix/Makefile ($(objpfx)wordexp-tst.out): Use
	$(test-program-prefix-before-env), $(run-program-env) and
	$(test-program-prefix-after-env).
	* posix/tst-getconf.sh: Do not set environment variables
	explicitly.
	* posix/wordexp-tst.sh: Use test_program_prefix_before_env,
	run_program_env and test_program_prefix_after_env arguments.
	* stdio-common/tst-printf.sh: Do not set environment variables
	explicitly.
	* stdlib/Makefile ($(objpfx)tst-fmtmsg.out): Use
	$(test-program-prefix-before-env), $(run-program-env) and
	$(test-program-prefix-after-env).
	* stdlib/tst-fmtmsg.sh: Use test_program_prefix_before_env,
	run_program_env and test_program_prefix_after_env arguments.
	Split $test calls into $test_pre and $test.
	* timezone/Makefile (build-testdata): Use
	$(built-program-cmd-before-env), $(run-program-env) and
	$(built-program-cmd-after-env).

localedata/ChangeLog:
	* Makefile ($(addprefix $(objpfx),$(CTYPE_FILES))): Use
	$(built-program-cmd-before-env), $(run-program-env) and
	$(built-program-cmd-after-env).
	($(objpfx)sort-test.out): Use $(test-program-prefix-before-env),
	$(run-program-env) and $(test-program-prefix-after-env).
	($(objpfx)tst-fmon.out): Use $(run-program-prefix-before-env),
	$(run-program-env) and $(run-program-prefix-after-env).
	($(objpfx)tst-locale.out): Use $(built-program-cmd-before-env),
	$(run-program-env) and $(built-program-cmd-after-env).
	($(objpfx)tst-trans.out): Use $(run-program-prefix-before-env),
	$(run-program-env), $(run-program-prefix-after-env),
	$(test-program-prefix-before-env) and
	$(test-program-prefix-after-env).
	($(objpfx)tst-ctype.out): Use $(test-program-cmd-before-env),
	$(run-program-env) and $(test-program-cmd-after-env).
	($(objpfx)tst-wctype.out): Likewise.
	($(objpfx)tst-langinfo.out): Likewise.
	($(objpfx)tst-langinfo-static.out): Likewise.
	* gen-locale.sh: Use localedef_before_env, run_program_env and
	localedef_after_env arguments.
	* sort-test.sh: Use test_program_prefix_before_env,
	run_program_env and test_program_prefix_after_env arguments.
	* tst-ctype.sh: Use tst_ctype_before_env, run_program_env and
	tst_ctype_after_env arguments.
	* tst-fmon.sh: Use run_program_prefix_before_env, run_program_env
	and run_program_prefix_after_env arguments.
	* tst-langinfo.sh: Use tst_langinfo_before_env, run_program_env
	and tst_langinfo_after_env arguments.
	* tst-locale.sh: Use localedef_before_env, run_program_env and
	localedef_after_env arguments.
	* tst-mbswcs.sh: Do not set environment variables explicitly.
	* tst-numeric.sh: Likewise.
	* tst-rpmatch.sh: Likewise.
	* tst-trans.sh: Use run_program_prefix_before_env,
	run_program_env, run_program_prefix_after_env,
	test_program_prefix_before_env and test_program_prefix_after_env
	arguments.
	* tst-wctype.sh: Use tst_wctype_before_env, run_program_env and
	tst_wctype_after_env arguments.
crypt: don't include ufc-crypt.h multiple times

The file has no inclusion guards, and contains typedefs that
cause errors when included multiple times with older (pre-C11)
compilers such as gcc 4.4.

Save the "#ifdef DOS" content to crypt-private.h even though
it's likely not particularly useful.