expr.c (expand_expr, [...]): Set RTX_UNCHANGING_P on returned MEM.
* expr.c (expand_expr, case SAVE_EXPR): Set RTX_UNCHANGING_P on
returned MEM.
(expand_expr_unaligned, case ARRAY_REF): Check that index is
a constant before comparing it; use tree_low_cst.
* tree.c (save_expr): Set TREE_READONLY.
(substitute_expr): Return inside of NON_LVALUE_EXPR.
(build, build1): Set TREE_READONLY if all operands are.
(build_index_type): If upper bound is a negative number, lower
bound is zero and sizetype is unsigned, use upper bound of one and
lower of zero.
From-SVN: r36979