PPC/AIX: [heap] Uncommit unused large object page memory.

src/base/platform/platform-aix.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Platform specific code for AIX goes here. For the POSIX comaptible parts
 // the implementation is in platform-posix.cc.
 
 #include <pthread.h>
 #include <semaphore.h>
 #include <signal.h>
@@ skipping 214 matching lines @@
   if (mprotect(base, size, prot) == -1) return false;
 
   return true;
 }
 
 
 bool VirtualMemory::UncommitRegion(void* base, size_t size) {
   return mprotect(base, size, PROT_NONE) != -1;
 }
 
+bool VirtualMemory::ReleasePartialRegion(void* base, size_t size,
+                                         void* free_start, size_t free_size) {
+  return munmap(free_start, free_size) == 0;
+}
+
 
 bool VirtualMemory::ReleaseRegion(void* base, size_t size) {
   return munmap(base, size) == 0;
 }
 
 
 bool VirtualMemory::HasLazyCommits() { return true; }
 }  // namespace base
 }  // namespace v8