runtime: correct iteration of large map values

The hash_next_and_deref was a dreg from a
previous large value scheme.

Fixes #1163.

R=r, r2
CC=golang-dev
https://golang.org/cl/2369043

src/pkg/runtime/hashmap.c

@@ -920,17 +920,6 @@ void
 	}
 }
 
-void*
-hash_next_and_deref(struct hash_iter *it)
-{
-	void *p;
-
-	p = hash_next(it);
-	if(it->h->indirectval)
-		p = *(void**)p;
-	return p;
-}
-
 // mapiterinit(hmap *map[any]any, hiter *any);
 void
 ·mapiterinit(Hmap *h, struct hash_iter *it)
@@ -940,7 +929,7 @@ void
 		return;
 	}
 	hash_iter_init(h, it);
-	it->data = hash_next_and_deref(it);
+	it->data = hash_next(it);
 	if(debug) {
 		prints("runtime.mapiterinit: map=");
 		·printpointer(h);
@@ -969,7 +958,7 @@ void
 	if(gcwaiting)
 		gosched();
 
-	it->data = hash_next_and_deref(it);
+	it->data = hash_next(it);
 	if(debug) {
 		prints("runtime.mapiternext: iter=");
 		·printpointer(it);

test/fixedbugs/bug311.go

@@ -0,0 +1,20 @@
+// $G $D/$F.go && $L $F.$A && ./$A.out
+
+// Copyright 2010 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+func main() {
+	m := make(map[string][1000]byte)
+	m["hi"] = [1000]byte{1}
+	
+	v := m["hi"]
+	
+	for k, vv := range m {
+		if k != "hi" || string(v[:]) != string(vv[:]) {
+			panic("bad iter")
+		}
+	}
+}