Draft: Memoize calls

[nordlow]

Yeah I know this has been discussed before reaching a conclusion by some that this best reside in a layer above dmd. I fail to agree so I'm gonna do an experiment nevertheless and be pragmatic and see if I can get something reliable working that cuts down on CI loads at work.

I'm gonna deal with time-dependent tokens __DATE__, __TIME__, __TIMESTAMP__ first as I'm not sure how much of a show-stopper those will be.

The remaining fingerprinting of input file mod times and content a la git should be straightforward.

Caching needs to store and mimic stdout and stderr like ccache does.

Token.sizeof is unchanged.

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[nordlow]

Member string is expected to be true. Is this a show-stopper?

[UplinkCoder]

not a v flag.
v means verbose and is for informational flags only.

[nordlow]

I see. Thanks. Am gonna use -cmemoize for now for easier grepping until someone propose the real name. :)

[RazvanN7]

do an experiment nevertheless and be pragmatic and see if I can get something reliable working that cuts down on CI loads at work.

@nordlow do you have any proof that this actually helps in any way? I think that we need a clear scenario where this is helpful and how this is better than just using makefile target dependencies.

At a first glance, I don't think that this brings any benefits.