[jdk17u-dev] RFR: 8319372: C2 compilation fails with "Bad immediate dominator info"

[Goetz Lindenmaier]

I backport this for parity with 17.0.12-oracle.

The change just removes one local optimization pattern in C2. 
The change did not apply well as there are differences in comment
and whitespace, and a different error message. 

Code wise the outermost if()  differs.
As the inner pattern matching is the same, the problem
exists similarly in 11.

Tests pass.

-------------

Commit messages:
 - Backport 7766785098816cfcdae3479540cdc866c1ed18ad

Changes: https://git.openjdk.org/jdk17u-dev/pull/2274/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=2274&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8319372
  Stats: 231 lines in 4 files changed: 171 ins; 60 del; 0 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/2274.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/2274/head:pull/2274

PR: https://git.openjdk.org/jdk17u-dev/pull/2274