Add a missing dependency to fix build.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351458 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-readobj/CMakeLists.txt b/tools/llvm-readobj/CMakeLists.txt
index b0550f3..389e348 100644
--- a/tools/llvm-readobj/CMakeLists.txt
+++ b/tools/llvm-readobj/CMakeLists.txt
@@ -1,6 +1,7 @@
 set(LLVM_LINK_COMPONENTS
   DebugInfoCodeView
   DebugInfoDWARF
+  Demangle
   Object
   BinaryFormat
   Support