libsanitizer: Replace memcpy with internal version in sanitizer_common

libsanitizer: Replace memcpy with internal version in sanitizer_common

When GCC is configured with --enable-target-optspace the compiler generates
a memcpy call in the Symbolizer constructor in sanitizer_symbolizer.cpp
when compiling for SPARC V8. Add HAVE_AS_SYM_ASSIGN to replace it with a
call to __sanitizer_internal_memcpy.

libsanitizer/ChangeLog:

	* sanitizer_common/Makefile.am (DEFS): Add @AS_SYM_ASSIGN_DEFS@.
	* sanitizer_common/Makefile.in: Regenerate.