[lworld] RFR: 8339481: [lworld] C2: Rename InlineTypeNode::IsInit to NotNull [v3]

[Marc Chevalier]

> Picked the proposed name I found the most fitting. Added a comment to address the concern in the issue.

Marc Chevalier has updated the pull request incrementally with one additional commit since the last revision:

  Forgot the comments...

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

Changes:
  - all: https://git.openjdk.org/valhalla/pull/1491/files
  - new: https://git.openjdk.org/valhalla/pull/1491/files/f9d4baaf..8c959a80

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=1491&range=02
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=1491&range=01-02

  Stats: 25 lines in 16 files changed: 0 ins; 0 del; 25 mod
  Patch: https://git.openjdk.org/valhalla/pull/1491.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1491/head:pull/1491

PR: https://git.openjdk.org/valhalla/pull/1491