build: Use curated clang -Wall instead of -Weverything for clang-cl

[jpnurmi]

In clang-cl, bare -Wall maps to -Weverything, which enables all warnings including -Wswitch-enum. Use /clang:-Wall to get the standard curated clang -Wall subset instead, and remove the many -Wno-* suppressions that were only needed to tame -Weverything.

See also:

• fix(logs): Allow null custom attributes without debug warning #1552
• Clang-cl should map /Wall to -Wall, not -Weverything llvm/llvm-project#102982

[supervacuus]

I actually appreciated the -Weverything feedback (even if unintentional) with explicit removal, because it forced us to fix a lot of buggy code since we introduced clang-cl. In particular, the trigger for this change being, -Wswitch-enum is a sensible warning, because it forces you to review all switch statements that switch on values of that enum when you introduce a new enum value, whereas default is a classic "covers-all" trap. I know it sounds pedantic, but I consider this quite valuable. I something is truly worthless, we can always deactivate it. The diff between -Weverything and -Wall is much bigger than the set of our counter flags.

[jpnurmi]

Ok, no problem. I thought it wasn't intentional. Perhaps we could then turn on -Weverything for one of the faster Linux builds, too?

[supervacuus]

Ok, no problem. I thought it wasn't intentional. Perhaps we could then turn on -Weverything for one of the faster Linux builds, too?

I mean, we can try to increase the warning level everywhere, but test this locally first because it always takes a little time to figure out what actually valuable feedback is and what is just noise.

Much more valuable would be to fix the CI configs where -Werror is currently turned off due to remaining warnings, though.