re PR rtl-optimization/42475 (ICE at -O1 and above: internal compiler error: in simplify_subreg, at simplify-rtx.c:4954)

	PR rtl-optimization/42475
	* combine.c (make_compound_operation) <case SUBREG>: Use mode of
	SUBREG_REG (x) instead of tem's mode.

	* gcc.dg/pr42475.c: New test.

From-SVN: r155430