tsan: correct llvm libc++ name


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@170326 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/ThreadSanitizer.rst b/docs/ThreadSanitizer.rst
index 4cf0e37..a7f6eb7 100644
--- a/docs/ThreadSanitizer.rst
+++ b/docs/ThreadSanitizer.rst
@@ -99,7 +99,7 @@
 
 ThreadSanitizer is in beta stage.  It is known to work on large C++ programs
 using pthreads, but we do not promise anything (yet).  C++11 threading is
-supported with llvm libstdc++.  The test suite is integrated into CMake build
+supported with llvm libc++.  The test suite is integrated into CMake build
 and can be run with ``make check-tsan`` command.
 
 We are actively working on enhancing the tool --- stay tuned.  Any help,