[lworld] RFR: 8244227: [lworld] Explore an implementation where the reference projection and value projection types are backed by a single class symbol [v7]

[Srikanth Adayapalam]

> This PR overhauls the existing implementation/representation of reference projection types  and the inline types so that both share the same underlying symbol, much like how an infinite family of parameterized types that originate from the same generic type are modelled using the same underlying symbol.

Srikanth Adayapalam has updated the pull request incrementally with one additional commit since the last revision:

  Revert overeager conversion of asSuper calls into isSubtype calls as when the goal is instanceof determination, the former is good enough.

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Changes:
  - all: https://git.openjdk.java.net/valhalla/pull/375/files
  - new: https://git.openjdk.java.net/valhalla/pull/375/files/c2f4f478..c976027d

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=valhalla&pr=375&range=06
 - incr: https://webrevs.openjdk.java.net/?repo=valhalla&pr=375&range=05-06

  Stats: 15 lines in 7 files changed: 3 ins; 0 del; 12 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/375.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/375/head:pull/375

PR: https://git.openjdk.java.net/valhalla/pull/375