RFR: 8306706: Support out-of-line code generation for MachNodes [v3]

[Quan Anh Mai]

> Hi,
> 
> This patch adds supports for MachNodes to emit an out-of-line piece of code in the stub section of the compiled method. This allows the separation of the uncommon path from the common one, which speeds up the common path a little bit and increases compiled code density. Please take a look and leave reviews.
> 
> Thanks a lot.

Quan Anh Mai has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:

 - trailing new lines
 - add microbenchmark
 - refactor

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/13602/files
  - new: https://git.openjdk.org/jdk/pull/13602/files/3b13e9e6..262e7a3b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13602&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13602&range=01-02

  Stats: 183807 lines in 2968 files changed: 138810 ins; 22591 del; 22406 mod
  Patch: https://git.openjdk.org/jdk/pull/13602.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13602/head:pull/13602

PR: https://git.openjdk.org/jdk/pull/13602