[docs] Update HowToReleaseLLVM documentation.

[thieta]

Summary

There was a bunch of references to bugzilla and other old
instructions in there. I have updated it to match the current
reality.

llvm/docs/HowToReleaseLLVM.rst

 #. Verify that the current git trunk is in decent shape by
    examining nightly tester and buildbot results.
 
 #. Bump the version in trunk to N.0.0git and tag the commit with llvmorg-N-init.
    If ``X`` is the version to be released, then ``N`` is ``X + 1``.
 
 ::
 
-  $ git tag -a llvmorg-N-init
+  $ git tag -sa llvmorg-N-init
 
 #. Clear the release notes in trunk.
 
 #. Create the release branch from the last known good revision from before the
    version bump.  The branch's name is release/X.x where ``X`` is the major version
    number and ``x`` is just the letter ``x``.
 
 #. All tags and branches need to be created in both the llvm/llvm-project and
    llvm/llvm-test-suite repos.
 
 Update LLVM Version
 ^^^^^^^^^^^^^^^^^^^
 
 After creating the LLVM release branch, update the release branches'
-``CMakeLists.txt`` versions from '``X.0.0git``' to '``X.0.0``'.
-
-In addition, the version numbers of all the Bugzilla components must be updated
-for the next release.
+version with the script in ``llvm/utils/release/bump-version.py``.
 
 Tagging the LLVM Release Candidates
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Tag release candidates:
 
 ::
 
-  $ git tag -a llvmorg-X.Y.Z-rcN
+  $ git tag -sa llvmorg-X.Y.Z-rcN
 
 The Release Manager must supply pre-packaged source tarballs for users.  This can
 be done with the export.sh script in utils/release.
 
 Tarballs, release binaries,  or any other release artifacts must be uploaded to
 GitHub.  This can be done using the github-upload-release.py script in utils/release.
 
 ::

 proceed.
 
 This will obviously not cover all OSs and distributions, so additional community
 validation is important. However, if community input is not reached before the
 release is out, all bugs reported will have to go on the next stable release.
 
 The official release managers are:
 
-* Major releases (X.0): Hans Wennborg
-* Stable releases (X.n): Tom Stellard
+* Even releases: Tom Stellard ([e-mail])
+* Odd releases: Tobias Hieta ([e-mail])
 
 The official release testers are volunteered from the community and have
 consistently validated and released binaries for their targets/OSs. To contact
-them, you should post on the `Discourse forums (Project 
+them, you should post on the `Discourse forums (Project
 Infrastructure - Release Testers). <https://discourse.llvm.org/c/infrastructure/release-testers/66>`_
 
 The official testers list is in the file ``RELEASE_TESTERS.TXT``, in the ``LLVM``
 repository.
 
 Community Testing
 -----------------
 
#. Download ``llvm-X.Y``, ``llvm-test-X.Y``, and the appropriate ``clang``
    performance regressions.
 
 #. Run the :doc:`release process <ReleaseProcess>`, if your platform is
    *different* than that which is officially supported, and report back errors
    only if they were not reported by the official release tester for that
    architecture.
 
 We also ask that the OS distribution release managers test their packages with
-the first candidate of every release, and report any *new* errors in Bugzilla.
+the first candidate of every release, and report any *new* errors in GitHub.
 If the bug can be reproduced with an unpatched upstream version of the release
 candidate (as opposed to the distribution's own build), the priority should be
 release blocker.
 
 During the first round of testing, all regressions must be fixed before the
 second release candidate is tagged.
 
 In the subsequent stages, the testing is only to ensure that bug
 fixes previously merged in have not created new major problems. *This is not
 the time to solve additional and unrelated bugs!* If no patches are merged in,
 the release is determined to be ready and the release manager may move onto the
 next stage.
 
 Reporting Regressions
 ---------------------
 
 Every regression that is found during the tests (as per the criteria above),
-should be filled in a bug in Bugzilla with the priority *release blocker* and
-blocking a specific release.
-
-To help manage all the bugs reported and which ones are blockers or not, a new
-"[meta]" bug should be created and all regressions *blocking* that Meta. Once
-all blockers are done, the Meta can be closed.
+should be filled in a bug in GitHub and added to the release milestone.
 
 If a bug can't be reproduced, or stops being a blocker, it should be removed
-from the Meta and its priority decreased to *normal*. Debugging can continue,
-but on trunk.
+from the Milestone. Debugging can continue, but on trunk.
 
 Backport Requests
 -----------------
 
 Instructions for requesting a backport to a stable branch can be found :doc:`here <GitHub>`.
 
 Triaging Bug Reports for Releases
 ---------------------------------
#. If a bug has been fixed and has a pull request created for backporting it,
    You should also review the bug yourself to ensure that it meets the requirements
    for committing to the release branch.
 
 #. Once a bug has been reviewed, add the release:reviewed label and update the
    issue's status to "Needs Merge".  Check the pull request associated with the
    issue.  If all the tests pass, then the pull request can be merged.  If not,
    then add a comment on the issue asking someone to take a look at the failures.
 
-#. Once the pull request has been merged push it to the official release branch:
-
-   ::
-
-      git checkout release/XX.x
-      git pull --ff-only https://github.com/llvm/llvm-project-release-prs release/XX.x
-      git push https://github.com/llvm/llvm-project release/XX.x:release/XX.x
+#. Once the pull request has been merged push it to the official release branch
+   with the script ``llvm/utils/git/sync-release-repo.sh``.
 
    Then add a comment to the issue stating that the fix has been merged along with
    the git hashes from the release branch.  Add the release:merged label to the issue
    and close it.
 
 
 Release Patch Rules
 -------------------

 #. *Before RC3/Final Major Release* Patches should be limited to critical
    bugs or regressions.
 
 #. *Bug fix releases* Patches should be limited to bug fixes or very safe
    and critical performance improvements.  Patches must maintain both API and
    ABI compatibility with the previous major release.
 
 
-Merging Patches
-^^^^^^^^^^^^^^^
-
-Use the ``git cherry-pick -x`` command to merge patches to the release branch:
-
-#. ``git cherry-pick -x abcdef0``
-
-#. Run regression tests.
-
 Release Final Tasks
 -------------------
 
 The final stages of the release process involves tagging the "final" release
 branch, updating documentation that refers to the release, and updating the
 demo page.
 
 Update Documentation

 
 Tag the LLVM Final Release
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Tag the final release sources:
 
 ::
 
-  $ git tag -a llvmorg-X.Y.Z
+  $ git tag -sa llvmorg-X.Y.Z
   $ git push https://github.com/llvm/llvm-project.git llvmorg-X.Y.Z
 
 Update the LLVM Website
 ^^^^^^^^^^^^^^^^^^^^^^^
 
 The website must be updated before the release announcement is sent out.  Here
 is what to do:
 

 
 Create a new post in the `Announce Category <https://discourse.llvm.org/c/announce>`_
 once all the release tasks are complete.  For X.0.0 releases, make sure to include a
 link to the release notes in the post.  For X.0.1+ releases, generate a changelog
 using this command and add it to the post.
 
 ::
 
-  $ git log --format="[%h %s](https://github.com/llvm/llvm-project/commit/%H)" llvmorg-X.0.N-1..llvmorg-X.0.N
+  $ git log --format="- %aN: [%s (%h)](https://github.com/llvm/llvm-project/commit/%H)" llvmorg-X.0.N-1..llvmorg-X.0.N
 
 Once the release has been announced add a link to the announcement on the llvm
 homepage (from the llvm-www repo) in the "Release Emails" section.