ssa: map range/next

cl/_testrt/makemap/in.go

@@ -4,9 +4,17 @@ func main() {
 	m := make(map[int]string)
 	m[1] = "hello"
 	m[2] = "world"
-	println(m[1], m[2])
-	v, ok := m[2]
-	println(v, ok)
-	v2, ok := m[10]
-	println(v2, ok)
+	m[3] = "llgo"
+	println(m[1], m[2], len(m))
+	for k, v := range m {
+		println(k, ":", v)
+	}
+	s := make(map[string]int, len(m))
+	for k, v := range m {
+		s[v] = k
+	}
+	id, ok := s["llgo"]
+	println("llgo", id, ok)
+	none, ok := s["go"]
+	println("go", none, ok)
 }