PR rtl-optimization/47166
	* reload1.c (emit_reload_insns): Disable the spill_reg_store
	mechanism for PRE_MODIFY and POST_MODIFY.
	(inc_for_reload): For PRE_MODIFY, return the insn that sets the
	reloadreg.

Co-Authored-By: Richard Sandiford <rdsandiford@googlemail.com>

From-SVN: r169144