dont assume .exe is the only executable extension on windows

[bbatha]

This should probably be a search over PATH_EXT in the future, but that may still have some edge cases. For instance, emscripten generates .js files which are intended to be executed and the user would likely not have in her PATH_EXT.

[koute]

Does this actually fix anything? I'm not against merging this; I'd just like to understand what impact it would have. Did you change this because it fixes an actual problem you were facing?

(On a side note: this function is kinda broken by design, and I'd love to remove it completely, but that would require that rust-lang/cargo#3670 gets fixed; alternatively we could always launch cargo with the --message-format json parameter and format the user-facing messages ourselves, but that seems like a huge amount of work for something as basic as printing out the filename of the file which cargo just generated.)

[bbatha]

Does this actually fix anything? I'm not against merging this; I'd just like to understand what impact it would have. Did you change this because it fixes an actual problem you were facing?

Ya cargo-web on windows doesn't detect .js files as executable so test and start don't pickup the built artifacts.

[koute]

Hmm... well, right now I don't entirely understand why this would work, but as I currently have no way of verifying it I'm going to take your word on it and merge it. (Setting up appveyor for cargo-web is already on my very long TODO list.)

Thanks!