regression: assert_eq cannot find panic with no_implicit_prelude

[Mark-Simulacrum]

This only works on 2015 edition. This code sample will fail to compile on beta but succeed on stable.

#![no_implicit_prelude]

fn _foo() {
    assert_eq!(10, 20);
}

cc @petrochenkov

[petrochenkov]

For all macros beside panic the underlying issue is fixed in #61629.
panic is special, #61629 describes the situation in more detail.

[petrochenkov]

#61971 implements a temporary solution, but I'd rather leave this as wontfix.

[pnkfelix]

Discussed at T-compiler meeting. Closing as wont-fix.

[petrochenkov]

#62002 provides a proper solution.

[m-ou-se]

#78343 would fix this.