7017008: G1: Turn on compressed oops by default.

Summary: Normally compressed oops is enabled when the maximum heap size is under a certain limit, except when G1 is also enabled. Remove this limitation. Also re-enable GCBasher testing with G1 on 64 bit windows in jprt.
Reviewed-by: jcoomes, brutisso, tonyp

make/jprt.properties

 #
-# Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2006, 2011, 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
@@ -357,6 +357,7 @@ jprt.my.windows.x64.test.targets = \
     ${jprt.my.windows.x64}-{product|fastdebug}-c2-GCBasher_ParallelGC, \
     ${jprt.my.windows.x64}-{product|fastdebug}-c2-GCBasher_ParNewGC, \
     ${jprt.my.windows.x64}-{product|fastdebug}-c2-GCBasher_CMS, \
+    ${jprt.my.windows.x64}-{product|fastdebug}-c2-GCBasher_G1, \
     ${jprt.my.windows.x64}-{product|fastdebug}-c2-GCBasher_ParOldGC, \
     ${jprt.my.windows.x64}-{product|fastdebug}-c2-GCOld_default, \
     ${jprt.my.windows.x64}-{product|fastdebug}-c2-GCOld_SerialGC, \

src/share/vm/runtime/arguments.cpp

@@ -1410,7 +1410,7 @@ void Arguments::set_ergonomics_flags() {
   // by ergonomics.
   if (MaxHeapSize <= max_heap_for_compressed_oops()) {
 #if !defined(COMPILER1) || defined(TIERED)
-    if (FLAG_IS_DEFAULT(UseCompressedOops) && !UseG1GC) {
+    if (FLAG_IS_DEFAULT(UseCompressedOops)) {
       FLAG_SET_ERGO(bool, UseCompressedOops, true);
     }
 #endif