compiler flag for "preview all"

[Bruce Carneal]

On Monday, 29 June 2020 at 23:31:16 UTC, Bruce Carneal wrote:
> One of the ideas floated at beerconf was that of a single 
> compiler flag activating all "preview" options.
[snip]
>
> PS: Also at beerconf Stefan Koch opined that turning on all 
> preview options might not be possible due to incompatibilities 
> of some sort which, if true, would be an excellent reason for 
> adding the capability.

Stefan was right.  ldc 1.22.0 seg faults when compiling with all 
preview flags set, manually, and trivially exercising dip 1008 by 
itself.

Could be that there are several additional fatal combinations.

I suggest that the compiler writers extend their test suites to 
exercise at least the "all previews enabled" + small-N-utilized 
permutations.