RFR: 8295110: RISC-V: Mark out relocations as incompressible

[Xiaolin Zheng]

This patch marks all relocations incompressible as pre-discussions at [1] and converts instructions to their 2-byte compressible counterparts as much as possible when UseRVC is enabled.

Chaining PR #10421.

1. Code size reduction rate: about ~17% now after this patch under RVC, meaning if there's a piece of code of 1000 bytes, it may shrink to 830 bytes when RVC is enabled. [2]
2. Performance: conservatively no regressions observed. [3]

Having tested several times hotspot tier1~tier4; Testing another turn on board.



[1] https://mail.openjdk.org/pipermail/riscv-port-dev/2022-September/000615.html
[2] https://mail.openjdk.org/pipermail/riscv-port-dev/2022-September/000633.html
[3] https://mail.openjdk.org/pipermail/riscv-port-dev/2022-October/000656.html

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Commit messages:
 - [7] Blacklist mode
 - [6] RVC: IncompressibleRegions for relocations

Changes: https://git.openjdk.org/jdk/pull/10643/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10643&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8295110
  Stats: 207 lines in 13 files changed: 50 ins; 25 del; 132 mod
  Patch: https://git.openjdk.org/jdk/pull/10643.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10643/head:pull/10643

PR: https://git.openjdk.org/jdk/pull/10643