Adjust documentation for git migration.

This fixes most references to the paths:
 llvm.org/svn/
 llvm.org/git/
 llvm.org/viewvc/
 github.com/llvm-mirror/
 github.com/llvm-project/
 reviews.llvm.org/diffusion/

to instead point to https://github.com/llvm/llvm-project.

This is *not* a trivial substitution, because additionally, all the
checkout instructions had to be migrated to instruct users on how to
use the monorepo layout, setting LLVM_ENABLE_PROJECTS instead of
checking out various projects into various subdirectories.

I've attempted to not change any scripts here, only documentation. The
scripts will have to be addressed separately.

Additionally, I've deleted one document which appeared to be outdated
and unneeded:
  lldb/docs/building-with-debug-llvm.txt

Differential Revision: https://reviews.llvm.org/D57330

llvm-svn: 352514
GitOrigin-RevId: 5d71fc5d7b5ffe2323418a09db6eddaf84d6c662
diff --git a/docs/TipsAndTricks.rst b/docs/TipsAndTricks.rst
index d399da8..146da04 100644
--- a/docs/TipsAndTricks.rst
+++ b/docs/TipsAndTricks.rst
@@ -47,7 +47,7 @@
 the regression.
 
 LLVM has a single repository that contains all projects. It can be cloned at:
-`<https://github.com/llvm-project/llvm-project-20170507>`_. How to bisect on a
+`<https://github.com/llvm/llvm-project>`_. How to bisect on a
 git repository is explained here
 `<https://www.metaltoad.com/blog/beginners-guide-git-bisect-process-elimination>`_.
 The bisect process can also be automated as explained here:
diff --git a/www/get_started.html b/www/get_started.html
index 5d2caba..5d3e004 100644
--- a/www/get_started.html
+++ b/www/get_started.html
@@ -33,20 +33,14 @@
 <h2> Manual </h2>
 <h3 id="source"> Get the code </h3>
 
-<p><b>Warning:</b> Polly/LLVM/clang need to be checked out at the same time.</p>
-
 <pre>
-git clone http://llvm.org/git/llvm.git llvm_git
-git clone http://llvm.org/git/polly.git llvm_git/tools/polly
-
-# Also build the matching clang-version (optional)
-git clone http://llvm.org/git/clang.git llvm_git/tools/clang
+git clone http://github.com/llvm/llvm-project.git llvm_git
 </pre>
 <h3 id="build">Build Polly</h3>
 
 <pre>
 mkdir llvm_build && cd llvm_build
-cmake ../llvm_git && make
+cmake -DLLVM_ENABLE_PROJECTS='polly;clang' ../llvm_git/llvm && make
 </pre>
 
 <h3> Test Polly</h3>
@@ -59,7 +53,7 @@
 build. To configure Polly to use a pre-built LLVM, set the
 <code>-DCMAKE_PREFIX_PATH</code> option:
 
-<pre>cmake -DCMAKE_PREFIX_PATH=${LLVM_PREFIX}/lib/cmake/llvm</pre>
+<pre>cmake -DCMAKE_PREFIX_PATH=${LLVM_PREFIX}/lib/cmake/llvm ../llvm_git/polly</pre>
 
 To run unittests, however, you need to have the LLVM source directory around.
 Polly will use the <code>llvm-config</code> of the LLVM you're building against
diff --git a/www/menu.html.incl b/www/menu.html.incl
index da2bca6..07afd7b 100644
--- a/www/menu.html.incl
+++ b/www/menu.html.incl
@@ -34,7 +34,7 @@
     <a href="http://lab.llvm.org:8080/coverage/coverage-reports/polly/index.html">Code Coverage</a>
     <a href="http://llvm.org/reports/scan-build/">Static analysis</a>
     <a href="/doxygen/">Doxygen</a>
-    <a href="https://github.com/llvm-mirror/polly">Source @ GitHub</a>
+    <a href="https://github.com/llvm/llvm-project/tree/master/polly">Source @ GitHub</a>
   </div>
 
   <div class="submenu">
diff --git a/www/todo.html b/www/todo.html
index 8aa45c9..3624dc3 100644
--- a/www/todo.html
+++ b/www/todo.html
@@ -413,12 +413,6 @@
 
 </td></tr>
 <tr>
-<th align="left"> Git mirror
-</th><td class="done" align="center">
-git://llvm.org/git/polly.git
-</td><td> Tobias
-</td></tr>
-<tr>
 <th align="left"> Commit mails
 </th><td class="done" align="center">
 llvm-commits@lists.llvm.org