Added an answer about running the tests.

llvm-svn: 9498
diff --git a/llvm/docs/FAQ.html b/llvm/docs/FAQ.html
index ae9188a..ba71573 100644
--- a/llvm/docs/FAQ.html
+++ b/llvm/docs/FAQ.html
@@ -138,6 +138,20 @@
 	cases, this takes care of the problem.  To do this, just type <tt>make
 	clean</tt> and then <tt>make</tt> in the directory that fails to build.
+	<dt><b>I've built LLVM and am testing it, but the tests freeze.</b>
+	<dd>
+	This is most likely occurring because you built a profile or release
+	(optimized) build of LLVM and have not specified the same information on
+	the <tt>gmake</tt> command line.
+	<p>
+	For example, if you built LLVM with the command:
+	<p>
+	<tt>gmake ENABLE_PROFILING=1</tt>
+	<p>
+	...then you must run the tests with the following commands:
+	<p>
+	<tt>cd llvm/test<br>gmake  ENABLE_PROFILING=1</tt>