The crate name is already set in Cargo.toml. The comment says there is
some logic in the compiler that reads #![crate_name] and not
--crate-name, but I can't find it. Removing it seems to work fine.
// running tests while providing a base that other test frameworks may
// build off of.
-// N.B., this is also specified in this crate's Cargo.toml, but librustc_ast contains logic specific to
-// this crate, which relies on this attribute (rather than the value of `--crate-name` passed by
-// cargo) to detect this crate.
-
-#![crate_name = "test"]
#![unstable(feature = "test", issue = "50297")]
#![doc(test(attr(deny(warnings))))]
#![feature(libc)]