[foreign-abi] RFR: 8251047: GC stackwalking doesn't work when intrinsics are enabled [v2]

[Jorn Vernee]

> Hi,
> 
> This patch fixes GC stack walking for optimized native calls.
> 
> For calls in compiled frames, the callee argument oops are processed using special case code in
> `CompiledMethod::preserve_callee_argument_oops`. This code relies on the original bytecode to find the signature of the
> callee, but for optimized native calls this doesn't make sense, since the original call is replaced, and some of the
> arguments (notably some that are oops) are discarded. In the case of an optimized native call, we can skip all callee
> argument oop processing, since we can't pass any oops to native calls any ways.  Since the current code was already
> looking at debug info to find the signature of the callee, I piggy-backed on that to add a flag for optimized native
> calls. If the flag is set, we return early, skipping any processing.  (I left in the assert I used to debug this, since
> it gives the failure a better error message, should we run into this again in the future)  Thanks, Jorn

Jorn Vernee has updated the pull request with a new target base due to a merge or a rebase. The pull request now
contains three commits:

 - Explicitly save RBP location in thread anchor, so we can add it to the RegisterMap when jumping from the entry frame to
   the last java frame during a GC stack walk.
 - Skip optimized native calls when processing callee argument oops.
 - Add an assert to check whether a RegisterMap entry is NULL or not

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

Changes: https://git.openjdk.java.net/panama-foreign/pull/279/files
 Webrev: https://webrevs.openjdk.java.net/panama-foreign/279/webrev.01
  Stats: 58 lines in 15 files changed: 47 ins; 1 del; 10 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/279.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/279/head:pull/279

PR: https://git.openjdk.java.net/panama-foreign/pull/279