Cache One(...) constants

[ckaestne]

Instead of creating V.one(null) again and again, just cache those instructions and replace it by a static field access to the V library. The objects are immutable anyway.

Should work for all sequences of ICONST_1 + toInteger + v.One as well.

This won't have a big effect, but we repeat this over and over again when initializing fields and variables, such as $exceptionVar