typeck.c (build_binary_op): Issue warning if either operand of a comparison operator is a string literal...


	* typeck.c (build_binary_op): Issue warning if either operand of a
	comparison operator is a string literal, except for testing equality
	or inequality against NULL.

	* g++.dg/warn/Wstring-literal-comparison-1.C: New test case.
	* g++.dg/warn/Wstring-literal-comparison-2.C: Likewise.
	* g++.dg/warn/Wstring-literal-comparison-3.C: Likewise.
	* g++.dg/warn/Wstring-literal-comparison-4.C: Likewise.

From-SVN: r108120