ICE on attempt to compare deref of two functions ptr

[dlangBugzillaToGithub]

basile-z reported this on 2024-11-25T19:35:44Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=24881

Description

The following input

```
void function(int) a;
void function(int) b;

void main()
{
    const c = *a == *b;
    // assert(*a); // rejected during sema
}     
```

crashes dmd in the backend:

> TYD func
> 
> Program received signal SIGILL, Illegal instruction.
> 0x00005555559d1756 in dmd.backend.cod3.jmpopcode(dmd.backend.el.elem*) ()

I think however that the program is semantically invalid and should be rejected during exp-semantics, just like the commented assertion is.

[dlangBugzillaToGithub]

b2.temp commented on 2024-11-25T19:46:36Z

Seems to happen only with `is`, comparisons, and relationals operators.

[dlangBugzillaToGithub]

b2.temp commented on 2024-11-29T09:27:47Z

LDC2 crashes too since v1.35. Previously it generated bad code for `c` (see https://godbolt.org/z/cEM1MEevE), i.e `true` whatever the functions were pointing to.