[lworld] RFR: Make "PrimitiveParameterizedClass.default" a poly expression. [v4]

[Jesper Steen Møller]

> Make .default a separate node type in the parser.
> 
> ## Issue
> [JDK-8211914](https://bugs.openjdk.java.net/browse/JDK-8211914): [lworld] Javac should support type inference for default value creation
> 
> Note: The Linux x86 builds in GitHub actions seem to fail with something completely unrelated to these changes.

Jesper Steen Møller has updated the pull request incrementally with two additional commits since the last revision:

 - Whitespace fixes
 - Properly propagate reference projections for defaults, and add tests.

-------------

Changes:
  - all: https://git.openjdk.java.net/valhalla/pull/369/files
  - new: https://git.openjdk.java.net/valhalla/pull/369/files/0c088269..131b9c7d

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=valhalla&pr=369&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=valhalla&pr=369&range=02-03

  Stats: 19 lines in 3 files changed: 11 ins; 2 del; 6 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/369.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/369/head:pull/369

PR: https://git.openjdk.java.net/valhalla/pull/369