RFR: 8268873: Unnecessary Vector usage in java.base

[Andrey Turbanov]

Usage of thread-safe collection `Vector` is unnecessary. It's recommended to use `ArrayList` if a thread-safe implementation is not needed.
I checked only places where `Vector` was used as local variable.

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Commit messages:
 - [PATCH] Unnecessary Vector usage in java.base
 - [PATCH] Unnecessary Vector usage in JarIndex.read

Changes: https://git.openjdk.java.net/jdk/pull/4482/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4482&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8268873
  Stats: 18 lines in 3 files changed: 1 ins; 4 del; 13 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4482.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4482/head:pull/4482

PR: https://git.openjdk.java.net/jdk/pull/4482