The patches in this directory include some updates to tcc 0.9.25.
Some of them have been committed in the main tcc repository so
we will not need them in future updates.

In particular:

1. ELF file format (merged upstream)
   tcc 0.9.25 produces an ELF executable which is good for linux but
   not for FreeBSD. It misses the PHDR section which is almost
   mandatory for shared executables, puts in the .dynsym section
   some relocation info that FreeBSD expects to be in .got,
   and expect the relocation sections to be contiguous.

   patch-tccelf.c tries to address the above problem using
   conditional sections (so hopefully can be imported upstream)
   and also adds the ability to override the name of the dynamic
   loader through an environment variable (this is important to
   debug tcc).

   The resulting elf file is still not 100% correct -- if you strip it,
   the program will not run (presumably there is some dangling reference).
   Other than that, program do seem to run correctly.

2. predefined macros (partially merged upstream)
   patch-libtcc.c adds/fixes some predefined macros when compiling
   on FreeBSD: these are __FreeBSD__ and the usual set of
   __i386__ and __unix__ variants.
   It also #defines __builtin_inline(x,y), __PRETTY_FUNCTION__,
   __CC_SUPPORTS___INLINE, __aligned(x), __packed that are used
   in cdefs.h and by several user programs.
   Note that tcc recognises the __aligned__ and __packed__
   attributes but does not honor them.

3. -include, -M and other preprocessor directives
   patch-z1-preproc (name chosen because it must be applied after
   the other two) implements -include, -M (and related options),
   and makes tcc ignore -isystem and -std= which are often used
   to build code.