Merge pull request #3946 from anpol:export-tlvhbase

PiperOrigin-RevId: 461701938
Change-Id: I92601aeef9f0bb18a6d1c8b08e497d93dde4012a

googletest/include/gtest/internal/gtest-port.h

@@ -1710,7 +1710,7 @@ typedef GTestMutexLock MutexLock;
 // C-linkage.  Therefore it cannot be templatized to access
 // ThreadLocal<T>.  Hence the need for class
 // ThreadLocalValueHolderBase.
-class ThreadLocalValueHolderBase {
+class GTEST_API_ ThreadLocalValueHolderBase {
  public:
   virtual ~ThreadLocalValueHolderBase() {}
 };