tsan: add shadow memory flush + fix few bugs

llvm-svn: 157270
diff --git a/compiler-rt/lib/tsan/rtl/tsan_platform.h b/compiler-rt/lib/tsan/rtl/tsan_platform.h
index 61b8a69..5b2e62c 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_platform.h
+++ b/compiler-rt/lib/tsan/rtl/tsan_platform.h
@@ -65,6 +65,7 @@
 }
 
 uptr GetShadowMemoryConsumption();
+void FlushShadowMemory();
 
 const char *InitializePlatform();
 void FinalizePlatform();