libobjc

[Marcus G. Daniels]

With libobjc moved out of the compiler tree, it would be nice if it
could be built without references to the gcc sources.  To do this, it
appears that a couple macros would need to be compiled in libgcc:
BIGGEST_FIELD_ALIGNMENT and STRUCT_VALUE. 

ADJUST_FIELD_ALIGN, ROUND_TYPE_ALIGN, and ROUND_TYPE_SIZE, are also
used in libobjc.a, but these usages seem to be wrong to me -- they are
using Objective C type signatures as tree nodes -- I don't see how
this accomplishes anything.

The other referenced macros are constants and perhaps could be printed
by -print-objc-runtime-info.  They are STRUCTURE_SIZE_BOUNDARY,
PCC_BITFIELDS_TYPE_MATTERS, BITS_PER_UNIT and BITS_PER_WORD.