llvm-rc: Write depfile to location specified by the generator

Move the depfile flags to `CMAKE_DEPFILE_FLAGS_RC` so that they
are only usedwith generators that use depfiles.  Also switch to
using the `<DEPFILE>` placeholder for the location of the depfile
so that it goes where the generator expects.

Fixes: #20493

Modules/Platform/Windows-Clang.cmake

@@ -141,7 +141,8 @@ if("x${CMAKE_C_SIMULATE_ID}" STREQUAL "xMSVC"
         set(CMAKE_RC_PREPROCESSOR CMAKE_CXX_COMPILER)
       endif()
       if(DEFINED CMAKE_RC_PREPROCESSOR)
-        set(CMAKE_RC_COMPILE_OBJECT "${CMAKE_COMMAND} -E cmake_llvm_rc <OBJECT>.pp <${CMAKE_RC_PREPROCESSOR}> <DEFINES> -DRC_INVOKED <INCLUDES> <FLAGS> -clang:-MD -clang:-MF -clang:<SOURCE>.d -E <SOURCE> -- <CMAKE_RC_COMPILER> <DEFINES> /fo <OBJECT> <OBJECT>.pp")
+        set(CMAKE_DEPFILE_FLAGS_RC "-clang:-MD -clang:-MF -clang:<DEPFILE>")
+        set(CMAKE_RC_COMPILE_OBJECT "${CMAKE_COMMAND} -E cmake_llvm_rc <OBJECT>.pp <${CMAKE_RC_PREPROCESSOR}> <DEFINES> -DRC_INVOKED <INCLUDES> <FLAGS> -E <SOURCE> -- <CMAKE_RC_COMPILER> <DEFINES> /fo <OBJECT> <OBJECT>.pp")
         if(CMAKE_GENERATOR STREQUAL "Ninja")
           set(CMAKE_NINJA_CMCLDEPS_RC 0)
           set(CMAKE_NINJA_DEP_TYPE_RC gcc)