[wasm] Add guard regions to end of WebAssembly.Memory buffers

src/base/platform/platform-win32.cc

Index: src/base/platform/platform-win32.cc
diff --git a/src/base/platform/platform-win32.cc b/src/base/platform/platform-win32.cc
index 080e6bc0af9c6f631285adb810861e50fc2ce1ae..f1c7dc7d264d63cea87d438f164b4177cdefa182 100644
--- a/src/base/platform/platform-win32.cc
+++ b/src/base/platform/platform-win32.cc
@@ -821,6 +821,10 @@ void OS::Guard(void* address, const size_t size) {
   VirtualProtect(address, size, PAGE_NOACCESS, &oldprotect);
 }
 
+void OS::Unprotect(void* address, const size_t size) {
+  DWORD oldprotect;
+  VirtualProtect(address, size, PAGE_READWRITE, &oldprotect);
+}
 
 void OS::Sleep(TimeDelta interval) {
   ::Sleep(static_cast<DWORD>(interval.InMilliseconds()));