PR c++/84961
	* cp-tree.h (genericize_compound_lvalue): Declare.
	* typeck.c (genericize_compound_lvalue): New function.
	(unary_complex_lvalue, cp_build_modify_expr): Use it.
	* semantics.c (finish_asm_stmt): Replace MODIFY_EXPR, PREINCREMENT_EXPR
	and PREDECREMENT_EXPR in output and "m" constrained input operands with
	COMPOUND_EXPR.  Call cxx_mark_addressable on the rightmost
	COMPOUND_EXPR operand.

	* c-c++-common/pr43690.c: Don't expect errors on "m" (--x) and
	"m" (++x) in C++.
	* g++.dg/torture/pr84961-1.C: New test.
	* g++.dg/torture/pr84961-2.C: New test.

From-SVN: r258741