RFR: 8365570: C2 fails assert(false) failed: Unexpected node in SuperWord truncation: CastII [v6]

[Jasmine Karthikeyan]

> Hi all,
> This is a quick patch for the assert failure in superword truncation with CastII. I've added a check for all constraint cast nodes, and attached a reduced version of the fuzzer test. Thanks!

Jasmine Karthikeyan has updated the pull request incrementally with one additional commit since the last revision:

  Revert "Use Xcomp test run instead of Warmup(0)"
  
  This reverts commit 50bc132676e5a1276bdf2c236ae57873375a773d.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/26827/files
  - new: https://git.openjdk.org/jdk/pull/26827/files/50bc1326..0b445a5a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26827&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26827&range=04-05

  Stats: 2 lines in 1 file changed: 1 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/26827.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26827/head:pull/26827

PR: https://git.openjdk.org/jdk/pull/26827