Interal assertion triggered on a bad assignment inside a procedure return type declaration

[IAnkenman]

Context

Tested on two versions, both produce the same result:
Odin: dev-2025-01:47030501a && dev-2024-12-nightly:cf53404
OS: Windows 11 Home Basic (version: 24H2), build 26100.2605
CPU: Intel(R) Core(TM) Ultra 7 155H
RAM: 65033 MiB
Backend: LLVM 18.1.8

Expected Behavior

The compiler reports an error specifying why the assignment is invalid

Current Behavior

The compiler fails on an internal assertion.

Failure Information (for bugs)

Assertion Report:

C:\Projects\odin-lang\src\llvm_backend_utility.cpp(879): Assertion Failure: pt->Proc.calling_convention != ProcCC_Odin
exited with code -2147483645

The assertion report is the same in both tested versions, including the line number

Steps to Reproduce

Attempt to compile the following:

package main;

import "base:runtime";

foo :: proc () -> (allocator : runtime.Allocator = context.allocator) {
return;
}

main :: proc() -> () {
foo();
}