Work around a linker error caused by https://reviews.llvm.org/D56084.

This unbreaks all bots that build with -DLLVM_ENABLE_MODULES=1

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350650 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-mca/CMakeLists.txt b/tools/llvm-mca/CMakeLists.txt
index 1fceb08..fd39000 100644
--- a/tools/llvm-mca/CMakeLists.txt
+++ b/tools/llvm-mca/CMakeLists.txt
@@ -6,6 +6,8 @@
   AllTargetsDescs
   AllTargetsDisassemblers
   AllTargetsInfos
+  # FIXME: This works around a linker error with -DLLVM_BUILD_WITH_MODULES=1
+  CodeGen
   MCA
   MC
   MCParser