Update no_std support.

This `no_std` support isn't complete though, as some dependencies
don't support it.

lib/jit/src/target_tunables.rs

@@ -1,4 +1,4 @@
-use std::cmp::min;
+use core::cmp::min;
 use target_lexicon::{OperatingSystem, Triple};
 use wasmtime_environ::Tunables;