Jack Lu

note this depends on #15517 and https://github.com/ibmruntimes/openj9-openjdk-jdk19/pull/18

I've added review comments https://github.com/eclipse-openj9/openj9/pull/15766#discussion_r953142285, I think we need to address them before merging.

@keithc-ca can you please review this, thanks @tajila FYI

@keithc-ca can this PR be merged or do you have any additional concern that you would like to see addressed?

FYI https://github.com/eclipse-openj9/openj9/commit/379aa5af7ee467af7cafb1abed9aa3e1fd3e041d seem to be the snapshot before incorrect merge

> See [#15128 (comment)](https://github.com/eclipse-openj9/openj9/issues/15128#issuecomment-1212427171). Copying reply from https://github.com/eclipse-openj9/openj9/issues/15128#issuecomment-1212436668 >This is expected as when a classfile is loaded by the VM, CP entries will be optimized by the JVM (items reordered...

@keithc-ca can you take another look

Per discussion with @LinHu2016, I included part of Lin's code to prepare a stack allocated J9VMThread for stackwalk with data from Continuation object, this helper will be shared by VM...

The current VMHelper function is what GC would need as they have code that specifically depends on a walkable J9VMThread passed to top level function which eventually would call `walkStackFrames`....

> Also note that `decompilationStack` will also need to be swapped like other roots. do `j2iFrame` also need to be swapped?