[jdk19] RFR: 8289093: BlockLocationPrinter fails to decode addresses with G1 [v2]

[Thomas Schatzl]

> Hi all,
> 
>   can I have reviews for this change that fixes an assertion failure when trying to add annotations to the hs_err file?
> 
> The `block_start` API from `CollectedHeap` assumes that useful values for all given addresses is returned, not asserting/crashing like some method deeper in the call chain does since [JDK-8270540](https://bugs.openjdk.org/browse/JDK-8270540), resulting in somewhat scrambled hs_err files and additional stack frames to look at in the debugger. 
> 
> Testing: local compilation, gha, tier1-3
> 
> Thanks,
>   Thomas

Thomas Schatzl has updated the pull request incrementally with one additional commit since the last revision:

  Fix return value to just return null

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

Changes:
  - all: https://git.openjdk.org/jdk19/pull/68/files
  - new: https://git.openjdk.org/jdk19/pull/68/files/e008106f..aa029e46

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk19&pr=68&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk19&pr=68&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk19/pull/68.diff
  Fetch: git fetch https://git.openjdk.org/jdk19 pull/68/head:pull/68

PR: https://git.openjdk.org/jdk19/pull/68