Support executing .bat script as a compiler on Windows

[luser]

rustc has code to execute a .bat script as a linker on Windows because it's difficult to otherwise use a script as a linker there:
https://github.com/rust-lang/rust/blob/d2048b6db375299b681d4f4728b8e7cad9f74d5f/src/librustc_codegen_llvm/back/link.rs#L59

In the Firefox build we don't currently pass compiler paths to cargo for build scripts to use because msys' path translation makes a mess of them (mostly because we're using sccache and having a space in the path breaks things):
https://searchfox.org/mozilla-central/rev/c07aaf12f13037c1f5a343d31f8291549e57373f/config/rules.mk#917

If this crate supported executing a .bat script as a compiler on Windows we could instead put everything we needed in there and simply pass the path to the .bat which ought to work.

[alexcrichton]

Seems reasonable to me to support! IIRC this is basically just testing for *.bat and then doing cmd /c ..., right?

[MolotovCherry]

Just want to chime in here that .cmd is another similar one (it's basically the same as .bat). Android ndk is using .cmd in the replace of clang (pass different target flags to clang to compile differently)

[nico-abram]

Would the correct place to do this be around here?

https://github.com/alexcrichton/cc-rs/blob/388bf178f6c857bb07bcc333ceb31032fbee686c/src/lib.rs#L2901-L2908

Just test for *.bat or *.cmd and if so change the command to cmd and prepend the "/c "{command}" args?