Comments only, no change to functionality

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_...

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

supports building cross compilers on the fly without need
for configure --enable-cross

   $ make cross          # all compilers
   $ make cross-TARGET   # only TARGET-compiler & its libtcc1.a

with TARGET one from
   i386 x86_64 i386-win32 x86_64-win32 arm arm64 arm-wince c67

Type 'make help' for more information

tccelf.c : force linking bcheck by adding elf symbol __bound_init
bcheck.c : use (size_t)1 for x86_64

Fixes 7e7e6148fdb4adbda936f80b5d4ac3d738908d95

    * define targetos=Windows when --enable-tcc32-mingw, --enable-cygwin, ...
    * use TARGETOS insteed HOST_OS when selecting PROGS
    * use "$(tccdir)" insteed $(tccdir) on install (spaces in path)
    * install tcc.exe too
    * produce bcheck.o when cross-compiling too (lib/Makefile)
    * force bcheck.o linking by compiling inside tcc_set_output_type()
      a dummy program with local array. Otherwise bcheck.o may be not linked.
    * replace %xz format specifier with %p in bcheck (don't supported on
      Windows)
    * call a __bound_init when __bound_ptr_add, __bound_ptr_indir,
      __bound_new_region, __bound_delete_region called.
      This is because a __bound_init inside ".init" section is not called
      on Windows for unknown reason.
    * print on stderr a message when an illegal pointer is returned:
        there is no segmentation violation on Windows for a program
        compiled with "tcc -b"
    * remove "C:" subdir on clean if $HOST_OS = "Linux"
    * default CFLAGS="-Wall -g -O0" insteed CFLAGS="-Wall -g -O2"
      to speed up compilation and more precise debugging.