RFR: 8371480: VerifyError after JDK-8369654

[Vicente Romero]

It seems like the fix for JDK-8369654 went too far simplifying the new algo equivalent to the more complex idiom: `erasure(lub(t))`
As defined in the mentioned fix, it could happen that the list of erased supertypes lists interfaces first followed by classes. Getting the first element in this list would yield an interface which won't then be equivalent to the idiom it is replacing. The current fix adds another operation that should minimize the list of supertypes and sort them classes first and then interfaces.

TIA

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Commit messages:
 - 8371480: VerifyError after JDK-8369654

Changes: https://git.openjdk.org/jdk/pull/28276/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28276&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8371480
  Stats: 142 lines in 3 files changed: 133 ins; 0 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/28276.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28276/head:pull/28276

PR: https://git.openjdk.org/jdk/pull/28276