[clang/test] Add missing dependency on llvm-cxxfilt.

This tool is needed by clang/test/CodeGen/Output/ppc-mmintrin.c.

llvm-svn: 360939
diff --git a/clang/test/CMakeLists.txt b/clang/test/CMakeLists.txt
index 939390d..9f6bcbb 100644
--- a/clang/test/CMakeLists.txt
+++ b/clang/test/CMakeLists.txt
@@ -107,6 +107,7 @@
     llvm-as
     llvm-bcanalyzer
     llvm-cat
+    llvm-cxxfilt
     llvm-dis
     llvm-lto2
     llvm-modextract