swift234

fix: select_enum_addr_inst does not specify that it reads from memory

This fixes <rdar://problem/18603195> Changing frontend to emit "select_enum_addr" instead of calling _doesOptionalHaveValue causes miscompiles with optimization

The same applies for the switch_enum_addr_inst, but currently no optimization checks for the MayRead memory attribute of
term-instructions. So for switch_enum_addr_inst the missing MayRead caused no problem.



Swift SVN r22700