RFR: 8343629: More MergeStore benchmark

[Shaojin Wen]

1. Added the putBytes4 benchmark, which corresponds to StringBuilder appendNull
2. Optimized the putChars4/setInt/setLong series of benchmarks to reduce extra overhead and more accurately reflect performance differences.

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Commit messages:
 - Merge remote-tracking branch 'upstream/master' into merge_store_bench_202410
 - Merge branch 'master' into merge_store_bench_202410
 - add putBytes4 and improved put

Changes: https://git.openjdk.org/jdk/pull/21659/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21659&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8343629
  Stats: 315 lines in 1 file changed: 71 ins; 51 del; 193 mod
  Patch: https://git.openjdk.org/jdk/pull/21659.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21659/head:pull/21659

PR: https://git.openjdk.org/jdk/pull/21659