toke.c: Avoid extra sv_setpv for foo <newline> =>

When parsing something like

    time
       =>

if there is a global override, the parser transforms ‘time’ into
‘CORE::GLOBAL::time’ before it looks at the next line to see if there
is a fat arrow.

If it finds a fat arrow, it has to set the name back to ‘time’.

After finding a fat arrow on the line following a bareword, it was
setting the name to what appears in the program source, even when
there was no global override.  We can skip that most of the time.

All that I said about global overrides applies to ‘our’ subs, too.
‘foo’ gets transformed into ‘ThatPackage::foo’ and needs to be changed
back.  I added a test, to make sure that is not accidentally broken.

I took the liberty of changing ((SVOP*)pl_yylval.opval)->op_sv to sv
at the same time, to make the code more readable.
Version multibump.
POSIX math: Use the Perl_ math APIs (C89) consistently.
big{num,rat,int}: use eval block to load Math::BigInt::Lite
bignum tests: use eval block to load Math::BigInt::Lite
bignum tests: use eval-block instead of eval-string
Increase $bigrat::VERSION to 0.37
Increase $bignum::VERSION to 0.38
Increase $bigint::VERSION to 0.37
ListUtil.xs: Temporary fix removing declaration after statement.

https://rt.cpan.org/Public/Bug/Display.html?id=98624
Remove -foo ambiguity warning

$ ./perl -e 'sub foo{} -foo'
Ambiguous use of -foo resolved as -&foo() at -e line 1.

There is no ambiguity there, since unary minus does not force
its argument to be a bareword; it simply exempts barewords from
strictures.

This warning also makes it harder to use constantly recently added
to POSIX.  To avoid that warning, for negative infinity you have to
write ‘- Inf’ or ‘-+Inf’, because the most natural way of writing it,
‘-Inf’, warns.

See <20140901014232.20757.qmail@lists-nntp.develooper.com> and
related messages.
perl.c: fix small bug on Android from commit 9054c81

Commit b33b7ab made PERL_LIB absolute when cross-compiling
on Android. Commit 9054c81 added incompatibility with
this. Now, only add "./" to run buildcustomize.pl when
miniperl is running with -T.
fpclass snan detection errors (cut-n-paste).
Fix my constant $var utf8 confusion

‘my some_constant $var’ tries to resolve some_constant to a package
name and then look that up, but, when using the value of the constant
to do a stash lookup, it was applying the utf8 flag if ‘use utf8’ was
in scope, even if the constant wasn’t utf8:

$ ./perl -Ilib -e 'use constant foo=>qq|\xc4\xb5|; BEGIN{${"\xc4\xb5::foo"}}; my foo $dog; print "ok\n"'
ok
$ ./perl -Ilib -e 'use constant foo=>qq|\xc4\xb5|; BEGIN{${"\xc4\xb5::foo"}}; use utf8; my foo $dog; print "ok\n"'
No such class foo at -e line 1, near "; my foo"
Execution of -e aborted due to compilation errors.
lex_utf8.t can run under miniperl

but needs the Unicode tables built
POSIX math: Add the opengroup URL for math.h
NV_INF/NV_NAN fallback where int32 is coerced to IEEE754 float.

This is the second-to-last fallback.  The last one uses explicit
1/0.0 and 0/0.0 which may cause consternation with some compilers.
The .i target should depend at least on perl.h and config.h.

While at it, do the same for the .s target.
Long double might have INFINITYL or NANL.
Sync up with meta after backports

This includes the inevitable reordering and some typo fixes

Note to committers that change Configure: when you add scans, thos will
only be included if used/referenced. You can force those in by adding a
reference in metaconfig.h