ww: separate package identity from declared name

selfhost/cmd/wcc/cgendecl.ww

@@ -2,7 +2,6 @@ package wcc;
 
 import os;
 import syntax;
-import strconv;
 
 fn cgfnparams(c: *cgen, params: *syntax.node) void = {
 	let p: *syntax.node = params;
@@ -518,6 +517,7 @@ fn cgfn(c: *cgen, fn_: *syntax.node) void = {
 	cgeninit(c);
 	c.fnname = fn_.str;
 	c.curmod = fn_.nmod;
+	c.cursource = fn_.sourceid;
 	c.fnret  = fn_.lhs;
 
 	// sret callee (#23): return type is plain TY_STRUCT > 24B.