Fix ThreadLocalImpl::getInstance for --disable-threads.

PR13114.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159210 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/ThreadLocal.cpp b/lib/Support/ThreadLocal.cpp
index 1095804..0587aae 100644
--- a/lib/Support/ThreadLocal.cpp
+++ b/lib/Support/ThreadLocal.cpp
@@ -30,10 +30,12 @@
   void **pd = reinterpret_cast<void**>(&data);
   *pd = const_cast<void*>(d);
 }
-const void* ThreadLocalImpl::getInstance() { return data; }
-void ThreadLocalImpl::removeInstance() {
+const void* ThreadLocalImpl::getInstance() {
   void **pd = reinterpret_cast<void**>(&data);
-  *pd = 0;
+  return *pd;
+}
+void ThreadLocalImpl::removeInstance() {
+  setInstance(0);
 }
 }
 #else