ww: separate package identity from declared name

selfhost/cmd/wcc/cgenexpr.ww

@@ -11,7 +11,6 @@ package wcc;
 
 import os;
 import syntax;
-import strconv;
 
 // cgfloatbits — materialise a float constant in X0: MOVQ the IEEE bits
 // into AX, PUSH, MOVSD off the stack into X0. Shared by N_FLOATLIT (bits