[PATCH 0/3] MR7231: rpcrt4, winedbg, winevulkan: Various small fixes for Clang 21 + -Werror.

[William Horvath (＠whrvth)]

I don't think these are serious problems, but Clang 21's defaults (from llvm-mingw nightly) were resulting in build failures with `--enable-werror` due to `-Wtautological-compare` and `-Wunused-function`. I hope that the buffer wrap checking is somewhat idiomatic/standard.

If necessary, I can split off the winevulkan change, but it seems minor enough to be grouped in this MR.