Fix volatile / atomic ops on bools and small aggregates

Boolean values and small aggregates have a different type in
args/allocas than in SSA values but the intrinsics for volatile and
atomic ops were missing the necessary casts to handle that.

Fixes #23550

src/test/run-pass/issue-23550.rs

@@ -0,0 +1,39 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(core)]
+#![allow(warnings)]
+
+use std::intrinsics;
+
+#[derive(Copy)]
+struct Wrap(i64);
+
+// These volatile and atomic intrinsics used to cause an ICE
+
+unsafe fn test_bool(p: &mut bool, v: bool) {
+    intrinsics::volatile_load(p);
+    intrinsics::volatile_store(p, v);
+    intrinsics::atomic_load(p);
+    intrinsics::atomic_cxchg(p, v, v);
+    intrinsics::atomic_store(p, v);
+    intrinsics::atomic_xchg(p, v);
+}
+
+unsafe fn test_immediate_fca(p: &mut Wrap, v: Wrap) {
+    intrinsics::volatile_load(p);
+    intrinsics::volatile_store(p, v);
+    intrinsics::atomic_load(p);
+    intrinsics::atomic_cxchg(p, v, v);
+    intrinsics::atomic_store(p, v);
+    intrinsics::atomic_xchg(p, v);
+}
+
+fn main() {}