auto merge of #10527 : eholk/rust/win64, r=alexcrichton

This was needed to access UEFI boot services in my new Boot2Rust experiment.

I also realized that Rust functions declared as extern always use the C calling convention regardless of how they were declared, so this pull request fixes that as well.

src/test/auxiliary/extern_calling_convention.rs

@@ -0,0 +1,37 @@
+// Copyright 2013 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.
+
+// Make sure Rust generates the correct calling convention for extern
+// functions.
+
+#[inline(never)]
+#[cfg(target_arch = "x86_64")]
+pub extern "win64" fn foo(a: int, b: int, c: int, d: int) {
+    assert!(a == 1);
+    assert!(b == 2);
+    assert!(c == 3);
+    assert!(d == 4);
+
+    println!("a: {:?}, b: {:?}, c: {:?}, d: {:?}",
+             a, b, c, d)
+}
+
+#[inline(never)]
+#[cfg(target_arch = "x86")]
+#[cfg(target_arch = "arm")]
+pub extern fn foo(a: int, b: int, c: int, d: int) {
+    assert!(a == 1);
+    assert!(b == 2);
+    assert!(c == 3);
+    assert!(d == 4);
+
+    println!("a: {:?}, b: {:?}, c: {:?}, d: {:?}",
+             a, b, c, d)
+}

src/test/run-pass/extern-calling-convention-test.rs

@@ -0,0 +1,20 @@
+// Copyright 2013 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.
+
+// xfail-fast: aux-build not compatible with fast
+// aux-build:extern_calling_convention.rs
+
+extern mod extern_calling_convention;
+
+use extern_calling_convention::foo;
+
+fn main() {
+    foo(1, 2, 3, 4);
+}