CMakeLists: Fix LLVM Usage In UICommon

This compile definition was removed in 68cbd2640d because it was complicated by changes in 50dc0ffbce. Thus, the LLVM disassembler would never be used in UICommon's Disassembler class.

Source/Core/UICommon/CMakeLists.txt

@@ -56,6 +56,7 @@ if(ENABLE_LLVM)
   find_package(LLVM CONFIG)
   if(LLVM_FOUND)
     message(STATUS "LLVM found, enabling LLVM support in disassembler")
+    target_compile_definitions(uicommon PRIVATE HAVE_LLVM)
     # Minimal documentation about LLVM's CMake functions is available here:
     # https://releases.llvm.org/16.0.0/docs/CMake.html#embedding-llvm-in-your-project
     # https://groups.google.com/g/llvm-dev/c/YeEVe7HTasQ?pli=1
@@ -69,6 +70,7 @@ if(ENABLE_LLVM)
     llvm_config(uicommon USE_SHARED
       mcdisassembler target ${LLVM_EXPAND_COMPONENTS}
     )
+    target_include_directories(uicommon PRIVATE ${LLVM_INCLUDE_DIRS})
   endif()
 endif()