Fix test for linux

Author: aschwaighofer

test/IRGen/metadata.swift

@@ -10,7 +10,10 @@ enum Singleton {
 
 // CHECK: @"$s1A1GC14zeroSizedFieldAA9SingletonOvpWvd" = hidden constant i{{(64|32)}} 0
 // Check that the instance start is after the header (at 8 or 16).
-// CHECK: _DATA__TtC1A1G = private constant {{.*}} { i32 128, i32 {{(16|8)}}
+// CHECK-macosx: _DATA__TtC1A1G = private constant {{.*}} { i32 128, i32 {{(16|8)}}
+// CHECK-ios: _DATA__TtC1A1G = private constant {{.*}} { i32 128, i32 {{(16|8)}}
+// CHECK-watchos: _DATA__TtC1A1G = private constant {{.*}} { i32 128, i32 {{(16|8)}}
+// CHECK-tvos: _DATA__TtC1A1G = private constant {{.*}} { i32 128, i32 {{(16|8)}}
 
 class G {
   var zeroSizedField = Singleton.only