Update the tcmalloc vendor branch to r144 (gperftools 2.0).

third_party/tcmalloc/vendor/src/windows/port.h

Index: third_party/tcmalloc/vendor/src/windows/port.h
diff --git a/third_party/tcmalloc/vendor/src/windows/port.h b/third_party/tcmalloc/vendor/src/windows/port.h
index 300c72d10b058d1a660a22558e1186633bf26cdc..e9a020656b36fd63ea3251de42a8d0bc4a0e2900 100644
--- a/third_party/tcmalloc/vendor/src/windows/port.h
+++ b/third_party/tcmalloc/vendor/src/windows/port.h
@@ -65,14 +65,15 @@
 
 /*
  * 4018: signed/unsigned mismatch is common (and ok for signed_i < unsigned_i)
- * 4244: otherwise we get problems when substracting two size_t's to an int
+ * 4244: otherwise we get problems when subtracting two size_t's to an int
  * 4288: VC++7 gets confused when a var is defined in a loop and then after it
  * 4267: too many false positives for "conversion gives possible data loss"
  * 4290: it's ok windows ignores the "throw" directive
  * 4996: Yes, we're ok using "unsafe" functions like vsnprintf and getenv()
+ * 4146: internal_logging.cc intentionally negates an unsigned value
  */
 #ifdef _MSC_VER
-#pragma warning(disable:4018 4244 4288 4267 4290 4996)
+#pragma warning(disable:4018 4244 4288 4267 4290 4996 4146)
 #endif
 
 #ifndef __cplusplus
@@ -414,10 +415,14 @@ inline unsigned int sleep(unsigned int seconds) {
   return 0;
 }
 
+// mingw64 seems to define timespec (though mingw.org mingw doesn't),
+// protected by the _TIMESPEC_DEFINED macro.
+#ifndef _TIMESPEC_DEFINED
 struct timespec {
   int tv_sec;
   int tv_nsec;
 };
+#endif
 
 inline int nanosleep(const struct timespec *req, struct timespec *rem) {
   Sleep(req->tv_sec * 1000 + req->tv_nsec / 1000000);