The wwstage checker resolved a module-qualified call/access mod.x by the
same-module preference in scopelookupprefer, so when the importing package's
name collides with a type/fn of the same leaf (package fnmatch with fn fnmatch;
package random with type random), the dot-lhs mod resolved to the same-leaf
SK_TYPE/SK_FN instead of the coexisting SK_USE import — the N_DOT module-qual
arm never fired and the call went nil-stamped (the D class of the asserttyped
gap audit: fnmatch 2, random 16). cstage resolves this via Sym.use_alias; this
ports the equivalent to wwstage.
Add scopelookupuselocal (a single-scope SK_USE lookup, twin of scopelookuptype)
and prefer SK_USE for a dot-lhs in exprtype's N_CALL and N_DOT arms, keyed on
the scope where scopelookupprefer landed so a local binding sharing a module's
leaf keeps value semantics. Scope-layer only — no type-identity touch (cstage
use_alias never reaches type_eq).
Drives the 901 gap-corpus D count to 0 (random_test now byte-id cs==ww).
Compiler binary unchanged (no such collision in its own source); 990-997 hold.
The separate fnmatch bare-enum-member cgen cs!=ww is unrelated (filed).
Hojun-Cho
884dbb402b