Invalid `self` import was made

Compiled Successfully when an invalid self import was made.

• Fixing this issue will also help gccrs to emit error code E0431 similiar to rustc.

• You can view the same on compiler-explorer

I tried this code from E0431:

#![allow(unused)]
fn main() {
use {self}; // error: `self` import can only appear in an import list with a
            //        non-empty prefix
}

I expected to see this happen:

• Give error like rustc. i.e.,

error[E0431]: `self` import can only appear in an import list with a non-empty prefix

Instead, this happened:

• Compiled Successfully.

Compiler returned: 0

Meta

• What version of Rust GCC were you using, git sha dba8bc5bf8247161b6eff4f738b6479382f770f2.
• gccrs (Compiler-Explorer-Build-gcc-22f4c74767bddcb9813dca06fc6a354a67d05343-binutils-2.40) 13.0.1 20230417 (experimental)

Start by compiling the minimal Rust reproducer with gccrs and compare its result with rustc. Trace how the frontend handles use {self};; done means gccrs rejects it with error E0431 and a matching diagnostic.