b1719530f4
Don't call `temporary_scope` twice. `mirror_expr_inner` calls `temporary_scope`. It then calls `make_mirror_unadjusted` which makes an identical call to `temporary_scope`. This commit changes the `mirror_expr_inner` to get the `temp_lifetime` out of the expression produced by `make_mirror_unadjusted`, similar to how it currently gets the type. r? `@cjgillot`