RFR: 8312077: Fix signed integer overflow, final part [v3]

[Dean Long]

> This is hopefully the last set of integer overflow fixes for hotspot.  Some of the counters I changed to unsigned are updated in platform-specific code, so I could use some help testing on arm, ppc,  riscv, and s390.

Dean Long has updated the pull request incrementally with one additional commit since the last revision:

  fix IndexSetWatch

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/14883/files
  - new: https://git.openjdk.org/jdk/pull/14883/files/7cc45534..ace9c66a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14883&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14883&range=01-02

  Stats: 3 lines in 2 files changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/14883.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14883/head:pull/14883

PR: https://git.openjdk.org/jdk/pull/14883