[lworld] RFR: 8244227: [lworld] Explore an implementation where the reference projection and value projection types are backed by a single class symbol [v5]

[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 two additional commits since the last revision:

 - Where possible prefer Types.isSubtype over Types.asSuper for loss less subtyping determination; Merge Two flavors of Types.asSuper into one; Make sure to switch to projection types for sucessful hierarchy lookup via asSuper
 - Reverse all changes made to Types.asSuper both at definition site and call sites.

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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/42fefb15..14e36283

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=valhalla&pr=375&range=04
 - incr: https://webrevs.openjdk.java.net/?repo=valhalla&pr=375&range=03-04

  Stats: 314 lines in 16 files changed: 235 ins; 31 del; 48 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