* alias.c (alias_sets_conflict_p): New function.
(mems_in_disjoint_alias_sets_p): Use it.
(readonly_fields_p): Moved from expr.c; check for record type.
(objects_must_conflict_p): New function.
* calls.c (expand_call): Use assign_temp as much as possible, use
readonly variant if assigned once, and don't set memory attributes.
(emit_library_call_value_1, store_one_arg): Likewise.
* integrate.c (expand_inline_function): Likewise.
* stmt.c (expand_asm_operands, expand_return): Likewise.
* expr.c (copy_blkmode_from_reg, store_constructor): Likewise.
(store_field, save_noncopied_parts, expand_expr): Likewise.
(expand_expr_unaligned): Likewise.
(readonly_fields_p): Moved to alias.c.
(safe_from_p): Rework handling of SAVE_EXPR.
MEMs ony conflict if alias sets conflict; likewise for INDIRECT_REF.
* function.c (struct temp_slot): Delete field ALIAS_SET; add TYPE.
(assign_stack_for_temp): Use objects_must_confict_p.
Set all memory attributes from type, if specified.
(mark_temp_slot): Mark TYPE field.
* tree.h (alias_sets_conflict_p, readonly_fields_p): New decls.
(objects_must_conflict_p): Likewise.
* stmt.c (expand_decl): Don't use assign_stack_temp in error case.
(add_case_node): No need to copy nodes anymore.