* configure.ac: Set ABI_TWEAKS_SRCDIR.
* configure.host: Set abi_tweaks_dir. Check for atomicity.h when
setting atomicity_dir. Override type_cpu for arm based targets.
* include/Makefile.am (host_headers): Add cxxabi_tweaks.h.
* libsupc++/cxxabi.h: Include bits/cxxabi.h. Don't declare __guard.
* libsupc++/guard.cc: Use definitions from cxxabi_tweaks.h.
* libsupc++/vec.cc: Ditto.
* config/cpu/arm/cxxabi_tweaks.h: New file.
* config/cpu/generic/cxxabi_tweaks.h: New file.
* */Makefile.in: Regenerate.
* configure: Regenerate.
From-SVN: r84032
