This makes us use one less tool from MSVC, and removes one more use of wine
in cross builds.
We replace the call to either rc/llvm-rc or windres with a wrapper script.
While the script is not strictly needed for the latter, we use a wrapper
in that case anyway because it's one step towards fixing bug 1498414.
For llvm-rc, however, we need a wrapper because llvm-rc doesn't preprocess
on its own, so the wrapper does that too.
The wrapper script also allows to deal with the default flags passed to
llvm-rc or windres, rather than inherit them from old-configure.
We also need to explicitly pass the codepage to llvm-rc, which was not
necessary with rc (presumably, llvm-rc has a different default).
While here, remove the unused WINDRES subst from js/src/old-configure.in.
Also, while here, we remove --use-temp-file, because as described in the
linked bug and in the windres manual page, it was used to work around bugs
on Windows 98 and earlier.
Differential Revision: https://phabricator.services.mozilla.com/D86312