Stop using the enum as a manifest constant.

[Claude]

On Sunday, 6 June 2021 at 10:47:54 UTC, Mathias LANG wrote:
> On Sunday, 6 June 2021 at 10:40:13 UTC, Jack Applegame wrote:
>>
>> That's not enough. Let's deprecate any use of enum as a 
>> manifest constant.
>
> I wouldn't go that far. `enum` are like `#define`, and there 
> *are* cases where you want them. E.g. when using them as define 
> arguments:
> ```D
> void foo (char[] fmt = DEFAULT_VALUE) { /* ... */ }
> ```

Yes, and if the memory layout is like in C, I would expect 
'immutable' variables to be addressable (in RO data segment), but 
not 'enum' constants (which would be simple rvalues, probably 
directly used as-is in assembly instructions).