Don't use a type guard with a type which is not an interface.

R=r,gri
DELTA=2  (0 added, 0 deleted, 2 changed)
OCL=18781
CL=18785

test/fixedbugs/bug113.go

@@ -13,7 +13,7 @@ func main() {
   i = 1;
   var v1 int = i;
   if foo1(v1) != 1 { panicln(1) }
-  var v2 int32 = i.(int).(int32);
+  var v2 int32 = int32(i.(int));
   if foo2(v2) != 1 { panicln(2) }
   var v3 int32 = i; // This implicit type conversion should fail at runtime.
   if foo2(v3) != 1 { panicln(3) }

test/ken/interbasic.go

@@ -86,7 +86,7 @@ main()
 	u64 = 765432;	ia[12] = u64;
 
 	s = ia[0];	if s != "xxx" { panicln(0,s); }
-	i32 = ia[1].(int).(int32);
+	i32 = int32(ia[1].(int));
 			if i32 != 12345 { panicln(1,i32); }
 	b = ia[2];	if b != true { panicln(2,b); }