RFR: Merge jdk:master

[J.Duke]

Hi all,

this is an _automatically_ generated pull request to notify you that there are 32 commits from the branch `jdk:master`that can **not** be merged into the branch `master`:

The following file contains merge conflicts:

- make/autoconf/toolchain.m4

All Committers in this [project](https://openjdk.java.net/census#lanai) have access to my [personal fork](https://github.com/openjdk-bot/lanai) and can therefore help resolve these merge conflicts (you may want to coordinate who should do this).
The following paragraphs will give an example on how to solve these merge conflicts and push the resulting merge commit to this pull request.
The below commands should be run in a local clone of your [personal fork](https://wiki.openjdk.java.net/display/skara#Skara-Personalforks) of the [openjdk/lanai](https://github.com/openjdk/lanai) repository.

# Ensure target branch is up to date
$ git checkout master
$ git pull https://github.com/openjdk/lanai.git master

# Fetch and checkout the branch for this pull request
$ git fetch https://github.com/openjdk-bot/lanai.git +6:openjdk-bot-6
$ git checkout openjdk-bot-6

# Merge the target branch
$ git merge master

When you have resolved the conflicts resulting from the `git merge` command above, run the following commands to create a merge commit:

$ git add paths/to/files/with/conflicts
$ git commit -m 'Merge jdk:master'


When you have created the merge commit, run the following command to push the merge commit to this pull request:

$ git push https://github.com/openjdk-bot/lanai.git openjdk-bot-6:6

_Note_: if you are using SSH to push commits to GitHub, then change the URL in the above `git push` command accordingly.

Thanks,
J. Duke

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

Commit messages:
 - 8253762: JFR: getField(String) should be able to access subfields
 - 8257670: sun/security/ssl/SSLSocketImpl/SSLSocketLeak.java reports leaks
 - 8257796: [TESTBUG] TestUseSHA512IntrinsicsOptionOnSupportedCPU.java fails on x86_32
 - 8257211: C2: Enable call devirtualization during post-parse phase
 - 8257572: Deprecate the archaic signal-chaining interfaces: sigset and signal
 - 8257718: LogCompilation: late_inline doesnt work right for JDK 8 logs
 - 8257799: Update JLS cross-references in java.compiler
 - 8254939: macOS: unused function 'replicate4_imm'
 - 8257805: Add compiler/blackhole tests to tier1
 - 8257817: Shenandoah: Don't race with conc-weak-in-progress flag in weak-LRB
 - ... and 22 more: https://git.openjdk.java.net/lanai/compare/e5906189...cef606fe

The webrev contains the conflicts with master:
 - merge conflicts: https://webrevs.openjdk.java.net/?repo=lanai&pr=140&range=00.conflicts

Changes: https://git.openjdk.java.net/lanai/pull/140/files
  Stats: 7995 lines in 154 files changed: 4524 ins; 2754 del; 717 mod
  Patch: https://git.openjdk.java.net/lanai/pull/140.diff
  Fetch: git fetch https://git.openjdk.java.net/lanai pull/140/head:pull/140

PR: https://git.openjdk.java.net/lanai/pull/140