builtins.c (fold_builtin): Don't generate NOP_EXPR that is going to be thrown away soon when IGNORE is set.

	* builtins.c (fold_builtin): Don't generate NOP_EXPR that is going
	to be thrown away soon when IGNORE is set.
	* tree-ssa-ccp.c (convert_to_gimple_builtin): Add IGNORE argument
	indicating when return value shall not be computed.
	* gimplify.c (internal_get_tmp_var): Avoid random tree sharing.

From-SVN: r118091