Fix failing CompilerTest.

Change-Id: I8208e60ffd7dafca02b4351877268fc05a714228
Allow JsInterop to work on Non-Interfaces

1. Added @JsNamespace, support for package-info and nested types
2. Hoist clinits for static exported fields and methods
3. Fixup CFA to rescue exported fields too
4. UnifyAST resolves package-info if it exists for JsNamespace
5. Extra tests

Change-Id: I23260d22822a0723f1f43dc9af1dadd8a7ae723a
Abort test case early if compilation failed.

Change-Id: I5ad844c11b7d1bc9170a66e295ca1fa23c489141