PR rtl-optimization/60131
	* ree.c (get_extended_src_reg): New function.
	(combine_reaching_defs): Use it rather than assuming location
	of REG.
	(find_and_remove_re): Verify first operand of extension is
	a REG before adding the insns to the copy list.

	PR rtl-optimization/60131
	* g++.dg/torture/pr60131.C: New test.

From-SVN: r207792