Using both no_mangle and export_name attributes should cause a warning

[gamozolabs]

In a simple example like:

#[no_mangle]
#[export_name = "asdf"]
pub extern fn foobar() {}

The actual exported name will be asdf. It seems export_name wins over no_mangle however there is no warning letting you know this occurred. It seems there is no valid use for having both of these so it's probably worth warning about.

-B

[sassman]

@rustbot claim