docs: Add information about helper scripts to HowToReleaseLLVM page

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llvm/trunk/docs/HowToReleaseLLVM.rst

 After creating the LLVM release branch, update the release branches'
 ``autoconf`` and ``configure.ac`` versions from '``X.Ysvn``' to '``X.Y``'.
 Update it on mainline as well to be the next version ('``X.Y+1svn``').
 Regenerate the configure scripts for both ``llvm`` and the ``test-suite``.
 
 In addition, the version numbers of all the Bugzilla components must be updated
 for the next release.
 
-Build the LLVM Release Candidates
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Tagging the LLVM Release Candidates
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-Create release candidates for ``llvm``, ``clang``, ``dragonegg``, and the LLVM
-``test-suite`` by tagging the branch with the respective release candidate
-number.  For instance, to create **Release Candidate 1** you would issue the
-following commands:
+Tag release candidates using the tag.sh script in utils/release.
 
 ::
 
-  $ svn mkdir https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_XYZ
-  $ svn copy https://llvm.org/svn/llvm-project/llvm/branches/release_XY \
-             https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_XYZ/rc1
-
-  $ svn mkdir https://llvm.org/svn/llvm-project/cfe/tags/RELEASE_XYZ
-  $ svn copy https://llvm.org/svn/llvm-project/cfe/branches/release_XY \
-             https://llvm.org/svn/llvm-project/cfe/tags/RELEASE_XYZ/rc1
-
-  $ svn mkdir https://llvm.org/svn/llvm-project/dragonegg/tags/RELEASE_XYZ
-  $ svn copy https://llvm.org/svn/llvm-project/dragonegg/branches/release_XY \
-             https://llvm.org/svn/llvm-project/dragonegg/tags/RELEASE_XYZ/rc1
-
-  $ svn mkdir https://llvm.org/svn/llvm-project/test-suite/tags/RELEASE_XYZ
-  $ svn copy https://llvm.org/svn/llvm-project/test-suite/branches/release_XY \
-             https://llvm.org/svn/llvm-project/test-suite/tags/RELEASE_XYZ/rc1
-
-Similarly, **Release Candidate 2** would be named ``RC2`` and so on.  This keeps
-a permanent copy of the release candidate around for people to export and build
-as they wish.  The final released sources will be tagged in the ``RELEASE_XYZ``
-directory as ``Final`` (c.f. :ref:`tag`).
+  $ ./tag.sh -release X.Y.Z -rc $RC
 
 The Release Manager may supply pre-packaged source tarballs for users.  This can
-be done with the following commands:
+be done with the export.sh script in utils/release.
 
 ::
 
-  $ svn export https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_XYZ/rc1 llvm-X.Yrc1
-  $ svn export https://llvm.org/svn/llvm-project/cfe/tags/RELEASE_XYZ/rc1 clang-X.Yrc1
-  $ svn export https://llvm.org/svn/llvm-project/dragonegg/tags/RELEASE_XYZ/rc1 dragonegg-X.Yrc1
-  $ svn export https://llvm.org/svn/llvm-project/test-suite/tags/RELEASE_XYZ/rc1 llvm-test-X.Yrc1
-
-  $ tar -cvf - llvm-X.Yrc1        | gzip > llvm-X.Yrc1.src.tar.gz
-  $ tar -cvf - clang-X.Yrc1       | gzip > clang-X.Yrc1.src.tar.gz
-  $ tar -cvf - dragonegg-X.Yrc1   | gzip > dragonegg-X.Yrc1.src.tar.gz
-  $ tar -cvf - llvm-test-X.Yrc1   | gzip > llvm-test-X.Yrc1.src.tar.gz
+  $ ./export.sh -release X.Y.Z -rc $RC
+
+This will generate source tarballs for each LLVM project being validated, which
+can be uploaded to the website for further testing.
 
 Building the Release
 --------------------
 
 The builds of ``llvm``, ``clang``, and ``dragonegg`` *must* be free of
 errors and warnings in Debug, Release+Asserts, and Release builds.  If all
 builds are clean, then the release passes Build Qualification.
 

 Subversion and changes in basic system requirements.  Merge both changes from
 mainline into the release branch.
 
 .. _tag:
 
 Tag the LLVM Final Release
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-Tag the final release sources using the following procedure:
+Tag the final release sources using the tag.sh script in utils/release.
 
 ::
 
-  $ svn copy https://llvm.org/svn/llvm-project/llvm/branches/release_XY \
-             https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_XYZ/Final
-
-  $ svn copy https://llvm.org/svn/llvm-project/cfe/branches/release_XY \
-             https://llvm.org/svn/llvm-project/cfe/tags/RELEASE_XYZ/Final
-
-  $ svn copy https://llvm.org/svn/llvm-project/dragonegg/branches/release_XY \
-             https://llvm.org/svn/llvm-project/dragonegg/tags/RELEASE_XYZ/Final
-
-  $ svn copy https://llvm.org/svn/llvm-project/test-suite/branches/release_XY \
-             https://llvm.org/svn/llvm-project/test-suite/tags/RELEASE_XYZ/Final
+  $ ./tag.sh -release X.Y.Z -final
 
 Update the LLVM Demo Page
 -------------------------
 
 The LLVM demo page must be updated to use the new release.  This consists of
 using the new ``clang`` binary and building LLVM.
 
 Update the LLVM Website