PR middle-end/20539
	* fold-const.c (fold_binary): Fix type mismatch between
	TRUTH_{AND,OR,XOR}_EXPR nodes an their operands' types.
	(fold_binary) <TRUTH_XOR_EXPR>: Avoid calling invert_truthvalue
	for non-truth-valued expressions.

	* c-common.c (c_common_truthvalue_conversion): Handle ERROR_MARK
	and FUNCTION_DECL in the main switch.
	<TRUTH_ANDIF_EXPR, TRUTH_ORIF_EXPR, TRUTH_AND_EXPR, TRUTH_OR_EXPR,
	TRUTH_XOR_EXPR>: When changing the result type of these tree nodes,
	we also need to convert their operands to match.
	<TRUTH_NOT_EXPR>: Likewise.

	* gcc.c-torture/compile/pr13066-1.c: New test case.
	* gcc.c-torture/compile/pr20539-1.c: Likewise.
	* g++.dg/opt/pr13066-1.C: Likewise.

From-SVN: r96777