reflect: reuse values during comparison of maps in DeepEqual

Change-Id: I82f999b8ed9434321a361bf1bcbed7cf6ee4bee6
Reviewed-on: https://go-review.googlesource.com/115475Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/reflect/deepequal.go

@@ -116,7 +116,7 @@ func deepValueEqual(v1, v2 Value, visited map[visit]bool, depth int) bool {
 		for _, k := range v1.MapKeys() {
 			val1 := v1.MapIndex(k)
 			val2 := v2.MapIndex(k)
-			if !val1.IsValid() || !val2.IsValid() || !deepValueEqual(v1.MapIndex(k), v2.MapIndex(k), visited, depth+1) {
+			if !val1.IsValid() || !val2.IsValid() || !deepValueEqual(val1, val2, visited, depth+1) {
 				return false
 			}
 		}