prog: don't pad data in exec encoding

With leb128 ints it does not make any sense.
Reduces exec sizes a bit more:

- exec sizes: 10%:597 50%:1438 90%:7145
+ exec sizes: 10%:584 50%:1423 90%:7076

1 files changed, 0 insertions, 1 deletions

diff --git a/prog/encodingexec_test.go b/prog/encodingexec_test.go
index 2a8ce30b3..19b7d1761 100644
--- a/prog/encodingexec_test.go
+++ b/prog/encodingexec_test.go
@@ -522,7 +522,6 @@ test() (async, rerun: 10)
 					want = binary.AppendVarint(want, int64(elem))
 				case []byte:
 					want = append(want, elem...)
-					want = append(want, make([]byte, ((len(elem)+7) & ^7)-len(elem))...)
 				default:
 					t.Fatalf("unexpected elem type %T %#v", e, e)
 				}