-Z no-trans support going away soon

[ehuss]

As of rust-lang/rust/pull/41751 -Z options are available on nightly only. This means that on-save syntax checking will stop working once this lands on beta/stable channels if you are using those toolchains. #165 already has support for cargo check and clippy, but it still defaults to -no-trans.

I will look into auto-detecting the rustc version and choosing either no-trans or cargo check based on what's available (I'm not sure how much of a performance impact that will have). This will also probably warrant some notes in the docs, since this will result in a loss of functionality (particularly rust_syntax_checking_include_tests).

[jasonwilliams]

Since your changes would bring a breaking change release anyway, should we not just move it to cargo check and tell people to upgrade to the latest rust if they want that feature. I think this would be easier than detecting their version.

[ehuss]

Sounds good to me. I was uncertain how quickly the average user upgrades their compiler, but the workaround (switching the config) is easy.

[jasonwilliams]

@ehuss im guessing we can close this issue now?

[ehuss]

I neglected to switch the default from -Zno-trans to "cargo check" in the branch on github. I just pushed a PR to switch the default, which will be required for 1.19.