[jdk11u-dev] RFR: 8271341: Opcode() != Op_If && Opcode() != Op_RangeCheck) || outcnt() == 2 assert failure with Test7179138_1.java

[Martin Doerr]

Clean Backport of JDK-8271341.

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Commit messages:
 - Backport 99fb12c798ad24cc4a671a666930ba42c3cd10c9

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/484/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=484&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8271341
  Stats: 19 lines in 2 files changed: 17 ins; 1 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/484.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/484/head:pull/484

PR: https://git.openjdk.java.net/jdk11u-dev/pull/484