Identical test files

[kud1ing]

The following test files are identical nowadays:

• https://github.com/mozilla/rust/blob/master/src/test/compile-fail/binop-typeck.rs and https://github.com/mozilla/rust/blob/master/src/test/compile-fail/type-mismatch.rs
• https://github.com/mozilla/rust/blob/master/src/test/compile-fail/issue-3993.rs and https://github.com/mozilla/rust/blob/master/src/test/compile-fail/issue-3993-3.rs
• https://github.com/mozilla/rust/blob/master/src/test/compile-fail/mod_file_disambig_aux.rs and https://github.com/mozilla/rust/blob/master/src/test/compile-fail/mod_file_disambig_aux/mod.rs

Can one of them go?

[sfackler]

The last two are intentionally there.

[kud1ing]

Is this documented?

[sfackler]

foo.rs and foo/mod.rs are two ways to specify the same module. Those are there to make sure that rustc complains.