re PR rtl-optimization/25514 (internal consistency failure)

	PR rtl-optimization/25514
	* combine.c (replaced_rhs_insn): New variable.
	(combine_instructions): Set replaced_rhs_insn when trying to replace
	a SET_SRC with a REG_EQUAL note.
	(distribute_notes): Use replaced_rhs_insn when determining the live
	range of a REG_DEAD register.

gcc/testsute
	* gcc.c-torture/compile/pr25514.c: New test.

From-SVN: r113983