PR middle-end/18548
	* expr.c (expand_expr_real_1) <MAX_EXPR>: Ensure that target, op0
	and op1 are all registers (or constants) before expanding the RTL
	comparison sequence [to avoid reg_overlap_mentioned (target, op1)].

	* gcc.dg/max-1.c: New test case.

From-SVN: r92351