Rollup merge of #41673 - bitshifter:repr-align-codegen-test, r=arielb1

Add simple `[repr(align)]` codegen test.

Checks alloca and memcpy are aligned correctly.

Test added to as additional check for #33626.

Author: frewsxcv

src/test/codegen/align-struct.rs

@@ -0,0 +1,57 @@
+// Copyright 2016 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.
+
+// compile-flags: -C no-prepopulate-passes
+#![crate_type = "lib"]
+
+#![feature(attr_literals)]
+#![feature(repr_align)]
+
+#[repr(align(64))]
+pub struct Align64(i32);
+
+pub struct Nested64 {
+    a: Align64,
+    b: i32,
+    c: i32,
+    d: i8,
+}
+
+pub enum Enum64 {
+    A(Align64),
+    B(i32),
+}
+
+// CHECK-LABEL: @align64
+#[no_mangle]
+pub fn align64(i : i32) -> Align64 {
+// CHECK: %a64 = alloca %Align64, align 64
+// CHECK: call void @llvm.memcpy.{{.*}}(i8* %{{.*}}, i8* %{{.*}}, i{{[0-9]+}} 64, i32 64, i1 false)
+    let a64 = Align64(i);
+    a64
+}
+
+// CHECK-LABEL: @nested64
+#[no_mangle]
+pub fn nested64(a: Align64, b: i32, c: i32, d: i8) -> Nested64 {
+// CHECK: %n64 = alloca %Nested64, align 64
+// CHECK: %a = alloca %Align64, align 64
+    let n64 = Nested64 { a, b, c, d };
+    n64
+}
+
+// CHECK-LABEL: @enum64
+#[no_mangle]
+pub fn enum64(a: Align64) -> Enum64 {
+// CHECK: %e64 = alloca %Enum64, align 64
+// CHECK: %a = alloca %Align64, align 64
+    let e64 = Enum64::A(a);
+    e64
+}