RFR: 8335977: Deoptimization fails with assert "object should be reallocated already" [v3]

[Cesar Soares Lucas]

> Please, review this patch to fix an issue that may occur when serializing debug information related to reduce allocation merges. The problem happens when there are more than one JVMS in a `uncommon_trap` and a _younger_ JVMS doesn't have the RAM inputs as a local/expression/monitor but an older JVMS does. In that situation the loop at line 1173 of output.cpp will set the `is_root` property of the ObjectValue to `false` when processing the younger JVMS even though it may have been set to `true` when visiting the older JVMS.
> 
> Tested on: 
>  - Win, Mac & Linux tier1-4 on x64 & Aarch64.
>  - CTW with some thousands of jars.

Cesar Soares Lucas has updated the pull request incrementally with one additional commit since the last revision:

  fix indentation

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/21624/files
  - new: https://git.openjdk.org/jdk/pull/21624/files/26b0b869..818b09e6

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21624&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21624&range=01-02

  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/21624.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21624/head:pull/21624

PR: https://git.openjdk.org/jdk/pull/21624