libclangSerialization also depends on the bitreader.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172910 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/CMakeLists.txt b/lib/Serialization/CMakeLists.txt
index 20999e1..1ed2474 100644
--- a/lib/Serialization/CMakeLists.txt
+++ b/lib/Serialization/CMakeLists.txt
@@ -1,3 +1,5 @@
+set(LLVM_LINK_COMPONENTS bitreader)
+
 add_clang_library(clangSerialization
   ASTCommon.h
   ASTReaderInternals.h