[jdk11u-dev] RFR: 8268672: C2: assert(!loop->is_member(u_loop)) failed: can be in outer loop or out of both loops only

[Martin Doerr]

Dependent PR for JDK-8268672 on top of JDK-8263303.

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Depends on: https://git.openjdk.java.net/jdk11u-dev/pull/339

Commit messages:
 - Backport d3ad8cd344681fe8442f821f97f05996bb972abe

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/341/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=341&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8268672
  Stats: 64 lines in 2 files changed: 62 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/341.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/341/head:pull/341

PR: https://git.openjdk.java.net/jdk11u-dev/pull/341