[clang] clang: improve lit testing docs (PR #178244)

[Aaron Ballman via cfe-commits]

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@@ -207,56 +207,53 @@ <h3 id="testingCommands">Testing on the Command Line</h3>
   <!--=====================================================================-->
 
   <p>If you want more control over how the tests are run, it may
-  be convenient to run the test harness on the command-line directly. Before
-  running tests from the command line, you will need to ensure that
-  <tt>lit.site.cfg</tt> files have been created for your build.  You can do
-  this by running the tests as described in the previous sections. Once the
-  tests have started running, you can stop them with control+C, as the
-  files are generated before running any tests.</p>
+  be convenient to run the test harness on the command-line directly. Running
+  the <tt>check-clang</tt> build target will result in the
+  <a href="https://llvm.org/docs/CommandGuide/lit.html">LLVM Integrated
+  Tester</a> (<tt>lit</tt>) generating a startup script to run tests for your
+  current configuration. Once the tests have started running, you can stop
+  them with <tt>control+C</tt>, as the files are generated before running any
+  tests.</p>
 
-  <p>Once that is done, to run all the tests from the command line,
-  execute a command like the following:</p>
+  <p>Once that is done, all the tests can be executed from the command line
+  by running the generated <tt>llvm-lit.cmd</tt> script as follows:</p>
----------------
AaronBallman wrote:

Does this script work on all platforms? (It sounds like it might be Windows-only because of the .cmd extension.) If not, we probably should continue to document the Python script instead so it's more generally applicable.

https://github.com/llvm/llvm-project/pull/178244