RFR: 8305324: C2: Wrong execution of vectorizing Interger.reverseBytes

[Daohan Qu]

This patch should fix [JDK-8305324](https://bugs.openjdk.org/browse/JDK-8305324).

`SuperWord::compute_vector_element_type()` implemented in `jdk/src/hotspot/share/opto/superword.cpp` propagates backward a narrower integer type when the upper bits of the value are not needed. However, `Integer.reverseBytes()` depends on higher-order bits of an integer and should be prevented from being narrowed and vectorized. Instead, it needs to be treated like `Math.abs()`( which is represented by `Op_AbsI` in the following code).

https://github.com/openjdk/jdk/blob/0243da2e4adc1b7ab6fcd5b10778532101158dce/src/hotspot/share/opto/superword.cpp#L3935-L3945

I have tested this patch for tier 1-3 on x86-64.

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Commit messages:
 - Add a jtreg test for 8305324
 - Prevent integer narrowed type backward propagation from passing through Op_ReverseBytesI operation, which should fix 8305324

Changes: https://git.openjdk.org/jdk/pull/13406/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13406&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8305324
  Stats: 57 lines in 2 files changed: 56 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/13406.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13406/head:pull/13406

PR: https://git.openjdk.org/jdk/pull/13406