clang/lib/Headers/CMakeLists.txt: Unbreak cmake build.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147373 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Headers/CMakeLists.txt b/lib/Headers/CMakeLists.txt
index 22f2281..4cb07e9 100644
--- a/lib/Headers/CMakeLists.txt
+++ b/lib/Headers/CMakeLists.txt
@@ -6,6 +6,7 @@
   bmi2intrin.h
   emmintrin.h
   float.h
+  fma4intrin.h
   immintrin.h
   iso646.h
   limits.h