RFR: 8301093: C2 fails assert(ctrl == kit.control()) failed: Control flow was added although the intrinsic bailed out

[Claes Redestad]

`must_be_not_null` can transform the graph, which will cause assert if intrinsification of `vectorizedHashCode` bails out after input validation. Solution is to move `must_be_not_null` to after the input validation.

Added regression test that invokes `ArraysSupport.vectorizedHashCode` with a non-constant type to trigger bailout.

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Commit messages:
 - whitespace
 - 8301093: C2 fails assert(ctrl == kit.control()) failed: Control flow was added although the intrinsic bailed out

Changes: https://git.openjdk.org/jdk/pull/12342/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12342&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8301093
  Stats: 71 lines in 2 files changed: 70 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/12342.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12342/head:pull/12342

PR: https://git.openjdk.org/jdk/pull/12342