Auto merge of #56051 - pietroalbini:rollup, r=pietroalbini

Rollup of 25 pull requests

Successful merges:

 - #55562 (Add powerpc- and powerpc64-unknown-linux-musl targets)
 - #55564 (test/linkage-visibility: Ignore on musl targets)
 - #55827 (A few tweaks to iterations/collecting)
 - #55834 (Forward the ABI of the non-zero sized fields of an union if they have the same ABI)
 - #55857 (remove unused dependency)
 - #55862 (in which the E0618 "expected function" diagnostic gets a makeover)
 - #55867 (do not panic just because cargo failed)
 - #55894 (miri enum discriminant handling: Fix treatment of pointers, better error when it is undef)
 - #55916 (Make miri value visitor useful for mutation)
 - #55919 (core/tests/num: Simplify `test_int_from_str_overflow()` test code)
 - #55923 (reword #[test] attribute error on fn items)
 - #55949 (ty: return impl Iterator from Predicate::walk_tys)
 - #55952 (Update to Clang 7 on CI.)
 - #55953 (#53488 Refactoring UpvarId)
 - #55962 (rustdoc: properly calculate spans for intra-doc link resolution errors)
 - #55963 (Stress test for MPSC)
 - #55968 (Clean up some non-mod-rs stuff.)
 - #55970 (Miri backtrace improvements)
 - #56007 (CTFE: dynamically make sure we do not call non-const-fn)
 - #56011 (Replace data.clone() by Arc::clone(&data) in mutex doc.)
 - #56012 (avoid shared ref in UnsafeCell::get)
 - #56016 (Add VecDeque::resize_with)
 - #56027 (docs: Add missing backtick in object_safety.rs docs)
 - #56043 (remove "approx env bounds" if we already know from trait)
 - #56059 (Increase `Duration` approximate equal threshold to 1us)

1 files changed, 80 insertions, 0 deletions

diff --git a/src/test/codegen/union-abi.rs b/src/test/codegen/union-abi.rs
new file mode 100644
index 00000000000..786968128ec
--- /dev/null
+++ b/src/test/codegen/union-abi.rs
@@ -0,0 +1,80 @@
+// Copyright 2017 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
+
+// This test that using union forward the abi of the inner type, as
+// discussed in #54668
+
+#![crate_type="lib"]
+#![feature(repr_simd)]
+
+#[derive(Copy, Clone)]
+pub enum Unhab {}
+
+#[repr(simd)]
+#[derive(Copy, Clone)]
+pub struct i64x4(i64, i64, i64, i64);
+
+#[derive(Copy, Clone)]
+pub union UnionI64x4{ a:(), b: i64x4 }
+
+// CHECK: define void @test_UnionI64x4(<4 x i64>* {{.*}} %arg0)
+#[no_mangle]
+pub fn test_UnionI64x4(_: UnionI64x4) { loop {} }
+
+pub union UnionI64x4_{ a: i64x4, b: (), c:i64x4, d: Unhab, e: ((),()), f: UnionI64x4 }
+
+// CHECK: define void @test_UnionI64x4_(<4 x i64>* {{.*}} %arg0)
+#[no_mangle]
+pub fn test_UnionI64x4_(_: UnionI64x4_) { loop {} }
+
+pub union UnionI64x4I64{ a: i64x4, b: i64 }
+
+// CHECK: define void @test_UnionI64x4I64(%UnionI64x4I64* {{.*}} %arg0)
+#[no_mangle]
+pub fn test_UnionI64x4I64(_: UnionI64x4I64) { loop {} }
+
+pub union UnionI64x4Tuple{ a: i64x4, b: (i64, i64, i64, i64) }
+
+// CHECK: define void @test_UnionI64x4Tuple(%UnionI64x4Tuple* {{.*}} %arg0)
+#[no_mangle]
+pub fn test_UnionI64x4Tuple(_: UnionI64x4Tuple) { loop {} }
+
+
+pub union UnionF32{a:f32}
+
+// CHECK: define float @test_UnionF32(float %arg0)
+#[no_mangle]
+pub fn test_UnionF32(_: UnionF32) -> UnionF32 { loop {} }
+
+pub union UnionF32F32{a:f32, b:f32}
+
+// CHECK: define float @test_UnionF32F32(float %arg0)
+#[no_mangle]
+pub fn test_UnionF32F32(_: UnionF32F32) -> UnionF32F32 { loop {} }
+
+pub union UnionF32U32{a:f32, b:u32}
+
+// CHECK: define i32 @test_UnionF32U32(i32)
+#[no_mangle]
+pub fn test_UnionF32U32(_: UnionF32U32) -> UnionF32U32 { loop {} }
+
+pub union UnionU128{a:u128}
+// CHECK: define i128 @test_UnionU128(i128 %arg0)
+#[no_mangle]
+pub fn test_UnionU128(_: UnionU128) -> UnionU128 { loop {} }
+
+#[repr(C)]
+pub union CUnionU128{a:u128}
+// CHECK: define void @test_CUnionU128(%CUnionU128* {{.*}} %arg0)
+#[no_mangle]
+pub fn test_CUnionU128(_: CUnionU128) { loop {} }
+