* Mark `error` as a `format` function, to properly scan its format
* Fix the call to error() from parser.y:
- Use '%s' to avoid passing an arbitrary format
- Simplify yyerror overall
* Fix size parameter of %.*s format being an int... bonkers standard.
* Report the number of arguments required and provided on a STRFMT mismatch
* Add an assert to check for a very unlikely bug
This applies to macro arguments, DB, DW, DL, DS,
PRINT, PRINTLN, EXPORT, PURGE, and OPT.
It also removes support for empty entries in DB/DW/DL.
(Deprecating it would require keeping parser support,
which is ambiguous with trailing commas.)
Fixes#753
Use C11 standard _Noreturn instead of attributes (except, of course, MSVC)
Remove unused helpers
Avoid trapping in release builds, in favor of just unreachability
Improve shim when __builtin_* are not available
