Follow-up #1 from step 2b: pack-fns that mix a non-pack
comptime param with the trailing pack (e.g. `tagged($tag: s32,
..$args)`). Today's `isPackFn` requires the pack to be the
ONLY comptime param; mixed shapes fall through to the inline
`lowerComptimeCall` path. That path adds non-string comptime
params to `comptime_param_nodes` for #insert substitution but
does NOT bind them as runtime locals, so the body's bare
`tag` reference hits "unresolved 'tag'" at the call site.
Next commit:
- Relax `isPackFn` to "exactly one trailing pack + any number
of non-pack comptime params" so the mono path takes over.
- Fold comptime VALUES into the mangled name (`tagged(7, ...)`
and `tagged(9, ...)` get distinct monos so each body sees
its own comptime constants).
- Bind comptime args as both `comptime_param_nodes` (for
#insert substitution) AND runtime locals (for bare-name
references). String literals stay as string locals;
int/bool/float literals become typed locals of the
appropriate primitive type.
This is the load-bearing prerequisite for step 6 (stdlib
`print`/`format` refactor to `(\$fmt, ..\$args)`) — without
mixed-mode mono support, stdlib stays on the inline path
forever.
203/203 example tests + `zig build test` green (the lock-in
captures the wrong-shape diagnostic as the snapshot to flip).
fc8a8c3f2e