CMake: Don't install llvm-tblgen twice

Summary:
The add_tablegen macros defines its own install target, and it was also calling
add_llvm_utility which adds another install target.

Configuring with -DLLVM_TOOLS_INSTALL_DIR set to something other than
'bin' along with -DLLVM_INSTALL_UTILS=ON was causing llvm-tablgen
to be installed to two separate directories.

Reviewers: beanz, hans

Reviewed By: beanz

Subscribers: llvm-commits, mgorny

Differential Revision: https://reviews.llvm.org/D30656

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297403 91177308-0d34-0410-b5e6-96231b3b80d8

cmake/modules/TableGen.cmake

@@ -99,7 +99,7 @@ macro(add_tablegen target project)
     set(LLVM_ENABLE_OBJLIB ON)
   endif()
 
-  add_llvm_utility(${target} ${ARGN})
+  add_llvm_executable(${target} DISABLE_LLVM_LINK_LLVM_DYLIB ${ARGN})
   set(LLVM_LINK_COMPONENTS ${${target}_OLD_LLVM_LINK_COMPONENTS})
 
   set(${project}_TABLEGEN "${target}" CACHE