win32/Makefile ("for cygwin") removed
- On cygwin, the normal ./configure && make can be used with either
  cygwin's "GCC for Win32 Toolchain"
      ./configure --cross-prefix=i686-w64-mingw32-
  or with an existing tcc:
      ./configure --cc=<old-tccdir>/tcc.exe

tcctest.c:
- exclude test_high_clobbers() on _WIN64 (does not work)

tests2/95_bitfield.c:
- use 'signed char' for ARM (where default 'char' is unsigned)

tests:
- remove -I "expr" diff option to allow tests with
  busybox-diff.

libtcc.c, tcc.c:
- removed -iwithprefix option.  It is supposed to be
  combined with -iprefix which we don't have either.

tccgen.c:
- fix assignments and return of 'void', as in
     void f() {
         void *p, *q;
         *p = *q:
         return *p;
     }
  This appears to be allowed but should do nothing.

tcc.h, libtcc.c, tccpp.c:
- Revert "Introduce VIP sysinclude paths which are always searched first"
  This reverts commit 1d5e386b0a78393ac6b670c209a185849ec798a1.

  The patch was giving tcc's system includes priority over -I which
  is not how it should be.

tccelf.c:
- add DT_TEXTREL tag only if text relocations are actually
  used (which is likely not the case on x86_64)
- prepare_dynamic_rel(): avoid relocation of unresolved
  (weak) symbols

tccrun.c:
- for HAVE_SELINUX, use two mappings to the same (real) file.
  (it was so once except the RX mapping wasn't used at all).

tccpe.c:
- fix relocation constant used for x86_64 (by Andrei E. Warentin)
- #ifndef _WIN32 do "chmod 755 ..." to get runnable exes on cygwin.

tccasm.c:
- keep forward asm labels static, otherwise they will endup
  in dynsym eventually.

configure, Makefile:
- mingw32: respect ./configure options --bindir --docdir --libdir
- allow overriding tcc when building libtcc1.a and libtcc.def with
      make XTCC=<tcc program to use>
- use $(wildcard ...) for install to allow installing just
  a cross compiler for example
      make cross-arm
      make install
- use name <target>-libtcc1.a

build-tcc.bat:
- add  options: -clean, -b bindir

This reverts commit 52622c3c0365ad497ce1188e433ac5f0a721c283.

Because 28b7c9 was right.

define uint64_t and int64_t as 'long' instead of 'long long'
when __LP64__ is define.

The port is functional. Bound checking is not supported yet.

fixes 5c35ba66c5ade4713bbd9c005e66889f6d7db293

Implementation was consistent within tcc but incompatible
with the ABI (for example library functions vprintf etc)

Also:
- tccpp.c/get_tok_str() : avoid "unknown format "%llu" warning
- x86_64_gen.c/gen_vla_alloc() : fix vstack leak