RFR: 8373508: C2: sinking CreateEx out of loop breaks the graph

[Roland Westrelin]

A `CreateEx` gets sunk out of loop by
`PhaseIdealLoop::try_sink_out_of_loop()` and, as a consequence, the
following logic:


  return (in(0)->is_CatchProj() && in(0)->in(0)->is_Catch() &&
          in(0)->in(0)->in(1) == in(1)) ? this : call->in(TypeFunc::Parms);


in `CreateExNode::Identity()` triggers which leads to the crash
because `call->in(TypeFunc::Parms)` is not even an object in this
particular case.

It's actually not clear to me what that logic in
`CreateExNode::Identity()` is expected to do and I wonder if it's
still needed.

Anyway, the fix I propose is to skip `CreateEx` in
`PhaseIdealLoop::try_sink_out_of_loop()`.

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Commit messages:
 - whitespaces
 - tests
 - more
 - fix

Changes: https://git.openjdk.org/jdk/pull/28842/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28842&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8373508
  Stats: 160 lines in 3 files changed: 160 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/28842.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28842/head:pull/28842

PR: https://git.openjdk.org/jdk/pull/28842