Add support for LLVM_NATIVE_TOOL_DIR flag

Author: adazem009

build/HunterPackages.cmake

@@ -58,6 +58,10 @@ set(HUNTER_LLVM_CMAKE_ARGS
     LLVM_TARGETS_TO_BUILD=host
 )
 
+if(LLVM_NATIVE_TOOL_DIR)  
+    set(HUNTER_LLVM_CMAKE_ARGS ${HUNTER_LLVM_CMAKE_ARGS} LLVM_NATIVE_TOOL_DIR=${LLVM_NATIVE_TOOL_DIR})  
+endif()
+
 if(CMAKE_BUILD_TYPE EQUAL "Debug")
     set(HUNTER_LLVM_CMAKE_ARGS ${HUNTER_LLVM_CMAKE_ARGS} LLVM_ENABLE_ASSERTIONS=ON)
 else()