gcc/
	* libfuncs.h (LTI_synchronize): New libfunc_index.
	(synchronize_libfunc): Declare.
	* builtins.c (expand_builtin_synchronize): Consider using
	synchronize_libfunc before falling back on an asm blockage.
	* config/mips/mips.c: Include libfuncs.h
	(mips_init_libfuncs): Initialize synchronize_libfunc for TARGET_MIPS16.

From-SVN: r137162