* tree.h (SAVE_EXPR_PERSISTENT_P): New macro.
	* tree.c (array_type_nelts): Don't handle SAVE_EXPRs specially.
	(unsave_expr_now): Don't unsave SAVE_EXPR_PERSISTENT_P
	expressions.
	* stor-layout.c (variable_size): Set SAVE_EXPR_PERSISTENT_P on
	variable-sized array bounds.

From-SVN: r30503