* config/rl78/rl78.c (rl78_addsi3_internal): New function.
	Optimizes the case where -mes0 is active and a constant symbolic
	address is used.
	* config/rl78/rl78-protos.h: Prototype the new function.
	* config/rl78/rl78.md (addsi3_internal_real): Call new function.

From-SVN: r226306