[llvm] Enable the use of SCCache for debug builds on Windows (PR #82371)

[Dave Abrahams via llvm-commits]

================
@@ -10,3 +10,9 @@ endif()
 if(POLICY CMP0116)
   cmake_policy(SET CMP0116 OLD)
 endif()
+
++# Enable debug info compatible with SCCache
++# https://github.com/mozilla/sccache?tab=readme-ov-file#usage
----------------
dabrahams wrote:

```suggestion
# MSVC debug information format flags are selected by an
# abstraction. New in CMake 3.25.
#
# Supports debug info with SCCache
# (https://github.com/mozilla/sccache?tab=readme-ov-file#usage)
# avoiding “fatal error C1041: cannot open program database; if
# multiple CL.EXE write to the same .PDB file, please use /FS"
```

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