eh-common.h (EH_ALLOC_SIZE, [...]): New #defines.

eh-common.h (EH_ALLOC_SIZE, [...]): New #defines.

gcc:
 	* eh-common.h (EH_ALLOC_SIZE, EH_ALLOC_ALIGN): New #defines.
	(eh_context): Add alloc_mask and alloc_buffer emergency fallback
	space.
	* libgcc2.c (__eh_alloc): Moved from cp/exception.cc. Fallback on
	emergency eh_context buffer, if malloc fails.
	(__eh_free): Moved from cp/exception.cc. Release to emergency
	eh_context buffer, if appropriate.
gcc/cp:
	* exception.cc: (__eh_alloc, __eh_free): Moved to libgcc2.c

From-SVN: r34429