[jdk21u-dev] RFR: 8315024: Vector API FP reduction tests should not test for exact equality

[Amos Shi]

Backport of [JDK-8315024](https://bugs.openjdk.org/browse/JDK-8315024)

Testing
- Local: Test passed on `MacOS 14.5`
  - `Double128VectorTests.java`: Test results: passed: 1
  - `Double256VectorTests.java`: Test results: passed: 1
  - `Double512VectorTests.java`: Test results: passed: 1
  - `Double64VectorTests.java`: Test results: passed: 1
  - `DoubleMaxVectorTests.java`: Test results: passed: 1
  - `Float128VectorTests.java`: Test results: passed: 1
  - `Float256VectorTests.java`: Test results: passed: 1
  - `Float512VectorTests.java`: Test results: passed: 1
  - `Float64VectorTests.java`: Test results: passed: 1
  - `FloatMaxVectorTests.java`: Test results: passed: 1
- Pipeline: 
- Testing Machine:

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Commit messages:
 - Backport e6f23a90d4a53339a3c9c2b76fc5d317940e4472

Changes: https://git.openjdk.org/jdk21u-dev/pull/750/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=750&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8315024
  Stats: 415 lines in 13 files changed: 295 ins; 0 del; 120 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/750.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/750/head:pull/750

PR: https://git.openjdk.org/jdk21u-dev/pull/750