re PR middle-end/92231 (ICE in gimple_fold_stmt_to_constant_1)

re PR middle-end/92231 (ICE in gimple_fold_stmt_to_constant_1)

	PR middle-end/92231
	* tree.h (fndecl_built_in_p): Use fndecl_built_in_p instead of
	DECL_BUILT_IN in comment.  Remove redundant ()s around return
	argument.
	* tree.c (free_lang_data_in_decl): Check if var is FUNCTION_DECL
	before calling fndecl_built_in_p.
	* gimple-fold.c (gimple_fold_stmt_to_constant_1): Check if
	TREE_OPERAND (fn, 0) is a FUNCTION_DECL before calling
	fndecl_built_in_p on it.
lto/
	* lto-lang.c (handle_const_attribute): Don't call fndecl_built_in_p
	on *node that is not FUNCTION_DECL.
testsuite/
	* gcc.c-torture/compile/pr92231.c: New test.

From-SVN: r277660