RFR: 8365047: Remove exception handler stub code in C2 [v7]

[Ruben]

> The C2 exception handler stub code is only a trampoline to the generated exception handler blob. This change removes the extra step on the way to the generated blob.
> 
> According to some comments in the source code, the exception handler stub code used to be patched upon deoptimization, however presumably these comments are outdated as the patching upon deoptimization happens for post-call NOPs only.

Ruben has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 10 commits:

 - Merge from the main branch
 - Address review comments
 - Address review comments
 - Address review comments
 - The patch is contributed by @TheRealMDoerr
 - Offset the deoptimization handler entry point
   
   Change-Id: I596317ec6a364b341e4642636fa5cf08f87ed722
 - Revert "Ensure stub code is not adjacent to a call"
 - Ensure stub code is not adjacent to a call
 - Address review comments
 - 8365047: Remove exception handler stub code in C2
   
   The C2 exception handler stub code is only a trampoline to the
   generated exception handler blob. This change removes the extra
   step on the way to the generated blob.
   
   According to some comments in the source code, the exception handler
   stub code used to be patched upon deoptimization, however presumably
   these comments are outdated as the patching upon deoptimization happens
   for post-call NOPs only.

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

Changes: https://git.openjdk.org/jdk/pull/26678/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26678&range=06
  Stats: 376 lines in 37 files changed: 98 ins; 212 del; 66 mod
  Patch: https://git.openjdk.org/jdk/pull/26678.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26678/head:pull/26678

PR: https://git.openjdk.org/jdk/pull/26678