[llvm] [CMake] Enable new policy for CMAKE_MSVC_DEBUG_INFORMATION_FORMAT (PR #82371)

[Martin Storsjö via llvm-commits]

================
@@ -10,3 +10,17 @@ endif()
 if(POLICY CMP0116)
   cmake_policy(SET CMP0116 OLD)
 endif()
+
++# Enable debug info compatible with SCCache
----------------
mstorsjo wrote:

At this point, this first line feels a bit out of place (and kinda redundant with the stuff on lines 20-23 below), can we just remove this one?

https://github.com/llvm/llvm-project/pull/82371