unhelpful error message on comptime store to `@constCast`ed pointer to comptime const

[mlugg]

Zig Version

0.15.0-dev.767+201c0f54a

Steps to Reproduce and Observed Output

//! repro.zig
comptime {
    const x: u32 = 42;
    const ptr: *u32 = @constCast(&x);
    ptr.* = 10;
}

$ zig build-obj repro.zig
repro.zig:5:11: error: unable to evaluate comptime expression
    ptr.* = 10;
    ~~~~~~^~~~
repro.zig:5:8: note: operation is runtime due to this operand
    ptr.* = 10;
    ~~~^~
repro.zig:2:1: note: 'comptime' keyword forces comptime evaluation
comptime {
^~~~~~~~

Expected Output

Something like this:

repro.zig:5:11: error: cannot store to constant memory
    ptr.* = 10;
    ~~~~~~^~~~