cmd/compile: cleaner solution for importing init functions

Using oldname+resolve is how typecheck handles this anyway.

Passes toolstash -cmp, with both -iexport enabled and disabled.

Change-Id: I12b0f0333d6b86ce6bfc4d416c461b5f15c1110d
Reviewed-on: https://go-review.googlesource.com/109715
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

src/cmd/compile/internal/gc/init.go

@@ -115,12 +115,18 @@ func fninit(n []*Node) {
 
 	// (6)
 	for _, s := range types.InitSyms {
-		if s.Def != nil && s != initsym {
-			n := asNode(s.Def)
-			n.checkInitFuncSignature()
-			a = nod(OCALL, n, nil)
-			r = append(r, a)
+		if s == initsym {
+			continue
+		}
+		n := resolve(oldname(s))
+		if n.Op == ONONAME {
+			// No package-scope init function; just a
+			// local variable, field name, or something.
+			continue
 		}
+		n.checkInitFuncSignature()
+		a = nod(OCALL, n, nil)
+		r = append(r, a)
 	}
 
 	// (7)

src/cmd/compile/internal/gc/noder.go

@@ -67,17 +67,6 @@ func parseFiles(filenames []string) uint {
 
 	localpkg.Height = myheight
 
-	if flagiexport {
-		// init.go requires all imported init functions to be
-		// fully resolved.
-		// TODO(mdempsky): Can this be done elsewhere more cleanly?
-		for _, s := range types.InitSyms {
-			if n := asNode(s.Def); n != nil && s.Pkg != localpkg {
-				resolve(n)
-			}
-		}
-	}
-
 	return lines
 }