moved target_machine defines to the <target>-gen.c files.
Also:
- c2str.c moved into conftest.c
- tccdefs.h ; defined(__TINYC__) && !defined(_LOCORE) removed
(in tinycc __TINYC__ is always defined and _LO... is never.)
- stddef.h : too many #ifdefs, removed
- tccgen.c:stabs: support win32 long doubles aka doubles.
- win32: math.h/tcc_libm.h: fix pointer mismatch in modfl
- tccpp.c: increment include_stack_ptr after the file was
actually found otherwise it would print
"in file included from <itself>: file not found..."
* alloca needs to be _alloca
* int64_t and uint64_t are also defined in <sys/_types/_int64_t.h>
but as long long, not as long, so adjust out <stddef.h> to agree
on Darwin
* define __APPLE_CC__ so that <TargetConditionals.h> correctly defines
various macros like TARGET_OS_MAC and TARGET_CPU_X86_64
Not wise if stddef.h was already included. This is related to commit
3aa26a794e
Instead hack stddef.h to have identical definition and thus
avoid the issue mentionned there.
(Because GNU's alloca.h unconditionally #undef's alloca)
Also, remove gcc specific sections in headers. and
instead change tests such that gcc does not use them.
