Compiler assertion when omitting parapoly parameter in return type

[IllusionMan1212]

Context

• Operating System & Odin Version:

        Odin:    dev-2024-11:e6475fec4
        OS:      Windows 11 Professional (version: 23H2), build 22631.4317
        CPU:     13th Gen Intel(R) Core(TM) i3-1315U
        RAM:     7835 MiB
        Backend: LLVM 18.1.8

Expected Behavior

Expected the compiler to error on the omitted parapoly parameter.

Current Behavior

Compiler asserts with llvm_backend_general.cpp(1856): Assertion Failure: "type != t_invalid" when building the below example.

Failure Information (for bugs)

The bug is reproducible with the below example. I believe it only happens when the parameter is omitted on a return type.

#3949 is a similar bug or if this is a duplicate then feel free to close it.

Steps to Reproduce

package main

Stack :: struct($Value: typeid) {
    top: ^StackNode(Value),
}

StackNode :: struct($Value: typeid) {
    next: ^StackNode(Value),
    v: Value,
}

pop_node :: proc(stack: ^Stack($T)) -> ^StackNode {
    popped := stack.top

    // Popping logic

    return popped
}

main :: proc() {
    stack: Stack(int)

    popped := pop_node(&stack)
}

The assertion goes away if we change the signature of pop_node to pop_node :: proc(stack: ^Stack($T)) -> ^StackNode(T)

Failure Logs

N/A