8080600: AARCH64: testlibrary does not support AArch64

Summary: Partial backport of 8080600 to make AArch64 a known platform
Reviewed-by: dholmes, coleenp

test/testlibrary/com/oracle/java/testlibrary/Platform.java

@@ -122,6 +122,10 @@ public class Platform {
         return isArch("(amd64)|(x86_64)");
     }
 
+    public static boolean isAArch64() {
+        return isArch("aarch64");
+    }
+
     private static boolean isArch(String archnameRE) {
         return Pattern.compile(archnameRE, Pattern.CASE_INSENSITIVE)
             .matcher(osArch)

test/testlibrary_tests/TestMutuallyExclusivePlatformPredicates.java

 /*
- * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -43,7 +43,7 @@ import java.util.Set;
  */
 public class TestMutuallyExclusivePlatformPredicates {
     private static enum MethodGroup {
-        ARCH("isARM", "isPPC", "isSparc", "isX86", "isX64"),
+        ARCH("isARM", "isPPC", "isSparc", "isX86", "isX64", "isAArch64"),
         BITNESS("is32bit", "is64bit"),
         OS("isAix", "isLinux", "isSolaris", "isWindows", "isOSX"),
         VM_TYPE("isClient", "isServer", "isGraal", "isMinimal"),