rl78-real.md (movqi_from_es): New pattern.

	* config/rl78/rl78-real.md (movqi_from_es): New pattern.
	* config/rl78/rl78.c (struct machine_function): Add uses_es field.
	(rl78_expand_prologue): Save the ES register in interrupt handlers
	that use it.
	(rl78_expand_epilogue): Restore the ES register if necessary.
	(rl78_start_function): Mention if the function uses the ES
	register.
	(rl78_lo16): Record the use of the ES register.
	(transcode_memory_rtx): Likewise.

From-SVN: r217911