This makes the asm symbols use the same members as the C symbols
for global decls, e.g. using the ELF symbol to hold offset and
section.  That allows us to use only one symbol table for C and
asm symbols and to get rid of hacks to synch between them.

We still need some special handling for symbols that come purely
from asm sources.

See testcase.  The C and asm symtab are still separate,
but integrated tighter: the asm labels are only synched at file
end, not after each asm snippet (this fixes references from one
to another asm block), the C and asm syms are synched both ways,
so defining things in asm and refering from C, or the other way
around works.  In effect this model reflects what happens with
GCC better.

For this the asm labels aren't using the C label namespace anymore,
but their own, which increases the size of each TokenSym by a pointer.

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

Comments only, no change to functionality

add some features for more complete 'long' support

tcc.h:
- use LONG_SIZE=4/8 instead of TCC_LONG_ARE_64_BIT
tccgen.c:
- add ptrdiff_type, update size_type
- support shift and ?: operations
- support long enum types
- display 'long' from type_to_str
- nwchar_t is unsigned short on windows
- unrelated: use memcpy in init_putv for long doubles to avoid
  random bytes in the image (if tcc was compiled by gcc) for
  diff purposes.
tccpp.c:
- make parse_number return correct types
- improve multi-character-constants 'XX' 'abcd'
Changelog:
- update

This commit fixed the problem that TCC directly cast each byte in wide string literal to wchar_t, which is wrong when wide string literal contains real wide chars.
It fixed the problem by assuming input charset is UTF-8, and wchar_t stores wide chars in UTF-16 (Windows) or UTF-32 (others).
The UTF-8 decoder is coded according to The Unicode Standard Version 10.

tccgen.c:
  doubles need to be aligned, on ARM.  The section_reserve()
  in init_putv does not do that.
-D ONE_SOURCE: is now the default and not longer needed. Also,
  tcc.h now sets the default native target.  These both make
  compiling tcc simple as "gcc tcc.c -o tcc -ldl" again.
arm-asm.c:
  enable pseudo asm also for inline asm
tests/tests2/Makefile:
  disable bitfield tests except on windows and x86_64
  and don't generate-always
tcc.c:
  fix a loop with -dt on errors
configure:
  print compiler version (as recognized)
tccpp.c:
  actually define symbols for tcc -dt
  clear static variables (needed for -dt or libtcc usage)
96_nodata_wanted.c:
  use __label__ instead of asm
lib/files:
  use native symbols (__i386__ etc.) instead of TCC_TARGET_...

* check that _Generic don't match unsigned char * with char *
  this case is usefull as with -funsigned-char, 'char *' are unsigned

* change VT_LONG so it's now a qualifier

  VT_LONG are never use for code generation, but only durring parsing state,
  in _Generic we need to be able to make diference between
  'long' and 'long long'
  So VT_LONG is now use as a type qualifier, it's old behaviour is still
  here, but we can keep trace of what was a long and what wasn't

* add TOK_CLONG and TOK_CULONG

  tcc was directly converting value like '7171L' into TOK_CLLONG or
  TOK_CINT depending of the machine architecture.

  because of that, we was unable to make diference between a long and a
  long long, which doesn't work with _Generic.

  So now 7171L is a TOK_CLONG, and we can handle _Generic properly

* check that _Generic can make diference between long and long long

* uncomment "type match twice" as it should now pass tests on any platforms

* add inside_generic global

  the point of this variable is to use VT_LONG in comparaison only
  when we are evaluating a _Generic.
  problem is with my lastest patchs tcc can now make the diference between
  a 'long long' and a 'long', but in 64 bit stddef.h typedef uint64_t as
  typedef signed long long int int64_t and stdint.h as unsigned long int, so tcc
  break when stdint.h and stddef.h are include together.

  Another solution woud be to modifie include/stddef.h so it define uint64_t as
  unsigned long int when processor is 64 bit, but this could break some
  legacy code, so for now, VT_LONG are use only inside generc.

* check that _Generic parse first argument correctly

* check that _Generic evaluate correctly exresion like "f() / 2"

* -dt now with lowercase t

* test snippets now separated by real preprocessor statements
  which is valid C also for other compilers

    #if defined test_xxx
       < test snippet x >
    #elif defined test_yyy
       < test snippet y >
    #elif ...
    #endif

* simpler implementation, behaves like -run if no 'test_...' macros
  are seen, works with -E too

* for demonstration I combined some of the small tests for errors
  and warnings (56..63,74) in "60_errors_and_warnings.c"

Also:
* libtcc.c:
  put tcc_preprocess() and tcc_assemble() under the setjmp clause
  to let them return to caller after errors.  This is for -dt -E.
* tccgen.c:
  - get rid of save/restore_parse_state(), macro_ptr is saved
    by begin_macro anyway, now line_num too.
  - use expr_eq for parsing _Generic's controlling_type
  - set nocode_wanted with const_wanted. too, This is to keep
    VT_JMP on vtop when parsing preprocessor expressions.
* tccpp.c: tcc -E: suppress trailing whitespace from lines with
  comments (that -E removes) such as
       NO_GOTPLT_ENTRY,\t    /* never generate ... */