[Patch/libsupc++]: Add CFLAGS, AM_CFLAGS to LTCOMPILE for C files

[Benjamin Kosnik]

>The LTCOMPILE rule definition for the two libiberty C demangler files
>in libsupc++ (GCC-3_3-branch) doesn't honour CFLAGS or AM_CFLAGS.
>
>Following corrects for 3_3-branch. so that optimized/debug code for these 
>files can be generated.

This is fine for gcc-3_3-branch.

>The LTCOMPILE define is also missing these flags on trunk.
>However, it makes no difference there now because of movement of
>functionality to src/demangle.cc.  Should it be changed there anyway or
>should LTCOMPILE and C_COMPILE just be be removed?

LTCOMPILE and C_COMPILE should just be removed from
libsupc++/Makefile.am on the trunk. This is pre-approved.

thanks,
benjamin