[libclang] Remove duplicate dependency on LLVMSupport

Differential Revision: https://reviews.llvm.org/D79451

Author: jkorous-apple

clang/tools/libclang/CMakeLists.txt

@@ -44,7 +44,6 @@ set(LIBS
   clangSema
   clangSerialization
   clangTooling
-  LLVMSupport
 )
 
 if (CLANG_ENABLE_ARCMT)