[embedded] Require macOS or Linux in test/embedded/no-allocations.swift

Author: kubamracek

test/embedded/no-allocations.swift

@@ -3,6 +3,7 @@
 // RUN: %target-swift-emit-ir %s -enable-experimental-feature Embedded -no-allocations -wmo -verify -verify-ignore-unknown
 
 // REQUIRES: swift_in_compiler
+// REQUIRES: OS=macosx || OS=linux-gnu
 
 public class X {} // expected-error {{cannot use allocating type 'X' in -no-allocations mode}}
 public func use_a_class() -> X {