fix bogus t/src/checkdepend.t warnings

PARROT_HAS_(CORE|EXTRA)_NCI_THUNKS is in %PConfig, not %PConfig_Temp.

Skip warning for src/gc/malloc.c /usr/include/malloc.h when
HAVE_USR_INCLUDE_MALLOC_H is undefined.

Skip warning for src/glut_nci_thunks.c glut_nci_thunks.str at all.
Enable VALGRIND tests with c_output test functions

E.g. POSTMORTEM=1 VALGRIND=tsan perl t/src/embed.t
or VALGRIND=valgrind perl t/src/extend.t
Enable VALGRIND tests with more test functions

Now also pir. E.g. VALGRIND=tsan prove `find t/src -name \*.t`
dynpmc/Rules: Revert OS build rules to pre 97aa16a

The rule to build os.str seems to be unnecessary and breaks nmake.
os.pmc actually needs os.str

I find this somewhat bizzare, given that it's basically empty, but
don't know how to fix that.  Instead of using the old nmake-breaking
rule, let the suffix rule in the main Makefile handle it.
dynpmc/os: nmake fix, $< invalid for os.str

$< is only valid for suffix rules, and also then not for nmake
Fixed dynpmc/os windows reveiled duplicate names

Fixed several bugs in the dummy dynpmc os:
The dynpmc/os was a static pmc. msvc could not link duplicate names.
I had to change the pmc to dynpmc, and had to rename the os to osdummy,
which is installed as os.so/bundle/dll. Tested ok on msvc.
[GH #832] TODO t/op/sprintf.t 217 on mingw (%+u prints +)
[GH #832] skip t/op/string.t 196,197 on mingw (%+u prints +)
[codingstd] t/perl/Parrot_IO.t copyright year
[GH #833] preload configure steps

Term::ReadLine does not work on my mingw, debugging configure steps is a pain.
E.g. "b postpone auto::snprintf::runstep" does not set a breakpoint when
debugging Configure.pl

I added a preloading of all steps into early Configure.pl so that breakpoints
can easily be set. The old handling is not changed.
.travis.yml: smoke threads branch also
.travis.yml: smoke more branches with less configurations

Add smoke-me branches and threads, but reduce the configurations a bit. Shuffle optimize and g++ a bit.
1-2 * 9 vs. now 3-4 * 5
Fix solaris gcc build: int3 trap not supported

Apparently the solaris 10 gcc assembler does not define the
int3 (0xCC) opcode. Disable it for solaris, i.e defined(sun).
gcc (GCC) 4.5.2 SunOS solaris 5.11 11.0 i86pc i386 i86pc

        "<stdin>", line 127437 : Illegal mnemonic
        Near line: "    int3"
        "<stdin>", line 127437 : Syntax error
        Near line: "    int3"
ChangeLog: note improved VALGRIND env
[GH #833] preload only when debugging perl via -d

As per jkeenans comment https://github.com/parrot/parrot/issues/833#issuecomment-8634064
ChangeLog: Add int3 trap fix on Solaris with gcc [GH #583]
[GH #836] Improve parsing pmc2c UNUSED arguments

UNUSED(arg) amcros are now detected in pmc bodies and change the argument declaration
to SHIM().
Empty bodies with return 1; are now detected and the two args are SHIMed.
UNUSED(interp) cause a new warning to be replaced by UNUSED(INTERP).
warnings: Improve clang support

clang requires warnings overrides for -Wno-parentheses-equality
and adds -Wno-unused-result to src/ops/core_ops.c.
(used in 29582199aef9ea9462 [GH #828] Optimize print_n/i and say_n/i)
Add ccwarn::src/ops/core_ops.c SUFFIX OVERRIDE for using (void)Parrot_io_write_b

Added with 29582199aef9ea94622b4202aee129521bc