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

src/base/platform/platform-aix.cc

Index: src/base/platform/platform-aix.cc
diff --git a/src/base/platform/platform-aix.cc b/src/base/platform/platform-aix.cc
index ea2824d8c3295451c2969745a8ecc889680e7a95..18b35b9066466bcf6c3b2c1a677e3abbccfd5663 100644
--- a/src/base/platform/platform-aix.cc
+++ b/src/base/platform/platform-aix.cc
@@ -232,6 +232,11 @@ 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;