[clang] clang/OpenCL: Fix assertion on call to function with addrspace argument (PR #115093)

[Alex Voicu via cfe-commits]

AlexVlx wrote:

> The following also currently crashes with the flags in question:
> 
> ```
> void use_of_private_var()
> {
>     int x = 0 ;
>     __private void* xx = &x;
> }
> ```
> 
> And the AST for the call in your testcase looks fine:
> 
> ```
>     `-CallExpr 0xd4aeec8 <line:7:5, col:19> 'void'
>       |-ImplicitCastExpr 0xd4aeeb0 <col:5> 'void (*)(__private int *__private)' <FunctionToPointerDecay>
>       | `-DeclRefExpr 0xd4aedf0 <col:5> 'void (__private int *__private)' Function 0xd4ae950 'private_ptr' 'void (__private int *__private)'
>       `-UnaryOperator 0xd4aee30 <col:17, col:18> '__private int *' prefix '&' cannot overflow
>         `-DeclRefExpr 0xd4aee10 <col:18> '__private int' lvalue Var 0xd4aed50 'x' '__private int'
> ```
> 
> I think this is actually a bug in the implementation of the "&" operator.

I’m not sure that’s a bug, I think that’s just the wonky OpenCL rules at play. I have a separate PR fixing this at the root which is stuck because @arsenm had objections and there’s a more robust way of handling ‘sret’, see #113930 

https://github.com/llvm/llvm-project/pull/115093