HowToReleaseLLVM: Add section about submitting patches for release branches

[hans]

Thanks for updating these!

docs/HowToReleaseLLVM.rst

342

The correct list might be cfe-commits for Clang, etc.

Also, I prefer when the merge request is made as a reply to the original commit message email, since it will then include the context automatically.

docs/HowToReleaseLLVM.rst

 the release is determined to be ready and the release manager may move onto the
 next stage.
 
 Release Patch Rules
 -------------------
 
 Below are the rules regarding patching the release branch:
 
-#. Patches applied to the release branch may only be applied by the release
-   manager.
+#. Patches applied to the release branch may only be applied with approval
+   from the code owner and the release manager.
 
 #. During the first round of testing, patches that fix regressions or that are
    small and relatively risk free (verified by the appropriate code owner) are
    applied to the branch.  Code owners are asked to be very conservative in
    approving patches for the branch.  We reserve the right to reject any patch
    that does not fix a regression as previously defined.
 
 #. During the remaining rounds of testing, only patches that fix critical
    regressions may be applied.
 
 #. For dot releases all patches must maintain both API and ABI compatibility with
    the previous major release.  Only bugfixes will be accepted.
 
+Nominating Patches for the Release Branch
+-----------------------------------------
+
+#. Send an email to llvm-commits and cc the code owner and release manager.
+   The email should contain the subject line:  **X.Y Merge Request: rXXXXXX**
+
+   Where X.Y is the LLVM version major and minor version, and rXXXXXX is the SVN
+   revision from trunk.
+
+#. If your email goes one week without a response, ping the patch.
+
+#. Once your patch has been approved by the code owner and the release manager
+   merge the patch into the release branch using the instructions below.
+
+#. If you don't have commit access or are unable to merge the patch, let the
+   release manager know.
+
+
 Merging Patches
 ^^^^^^^^^^^^^^^
 
 The ``utils/release/merge.sh`` script can be used to merge individual revisions
 into any one of the llvm projects. To merge revision ``$N`` into project
 ``$PROJ``, do:
 
 #. ``svn co https://llvm.org/svn/llvm-project/$PROJ/branches/release_XX