hg: kulla/dev/langtools: "null" generates bad code.

[robert.field at oracle.com]

Changeset: 806762df632a
Author:    rfield
Date:      2014-12-10 22:14 -0800
URL:       http://hg.openjdk.java.net/kulla/dev/langtools/rev/806762df632a

"null" generates bad code.
Contributed-by: bitterfoxc at gmail.com
Also new test infrastructure.

! repl/src/api/SnippetAnalysisImpl.java
! repl/test/KullaTesting.java
+ repl/test/NullTest.java