While digging into some sccache hashing details, I discovered that the MIDL compiler inserts a vanity comment header that includes a timestamp, the MIDL compiler's version, and a path to the source file. Wine appears to keep the timestamp consistent (in 2038), and the MIDL compiler's version is generally constant across build environments, but the path to the source file is different on Windows hosts (an absolute path) and Linux/macOS hosts (a relative path from the object directory to the source directory).

I think, but haven't confirmed, that the output line endings are \r\n regardless of the host environment.

This ticket tracks doing some light postprocessing in /build/midl.py so that these MIDL outputs are independent of the host environment.

This will help us get sccache hits when cross compiling.