message: Add `GetMemoryInfo` implementation in `tensorflow/core/platform/windows/port.cc`.
  The corresponding `AvailableRam` function doesn't need to appear in this file since it has a default implementation in `../platform/mem.h`.
diff: @@ -183,13 +183,15 @@ double NominalCPUFrequency() {
  return 1.0;
  }
  -int64 AvailableRam() {
  +MemoryInfo GetMemoryInfo() {
  + MemoryInfo mem_info = {INT64_MAX, INT64_MAX};
  MEMORYSTATUSEX statex;
  statex.dwLength = sizeof(statex);
  if (GlobalMemoryStatusEx(&statex)) {
  - return statex.ullAvailPhys;
  + mem_info.free = statex.ullAvailPhys;
  + mem_info.total = statex.ullTotalPhys;
  }
  - return INT64_MAX;
  + return mem_info;
  }
  int NumHyperthreadsPerCore() {
  