RFR: 8364588: Export the NPE backtracking functionality to general null-checking APIs [v2]

[Chen Liang]

> Provide a general facility for our null check APIs like Objects::requireNonNull or future Checks::nullCheck (void), converting the existing infrastructure to start tracking from a given stack site (depth offset) and a given stack slot (offset value).

Chen Liang has updated the pull request incrementally with one additional commit since the last revision:

  Web review
  
  Co-authored-by: David Holmes <62092539+dholmes-ora at users.noreply.github.com>

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Changes:
  - all: https://git.openjdk.org/jdk/pull/26600/files
  - new: https://git.openjdk.org/jdk/pull/26600/files/5735b802..09233e9a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26600&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26600&range=00-01

  Stats: 15 lines in 4 files changed: 2 ins; 3 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/26600.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26600/head:pull/26600

PR: https://git.openjdk.org/jdk/pull/26600