Adding -final-syntax-check to cpp11-migrate user docs

llvm-svn: 176758
diff --git a/clang-tools-extra/docs/cpp11-migrate.rst b/clang-tools-extra/docs/cpp11-migrate.rst
index 76385ee..9d11f12 100644
--- a/clang-tools-extra/docs/cpp11-migrate.rst
+++ b/clang-tools-extra/docs/cpp11-migrate.rst
@@ -26,10 +26,6 @@
 Command Line Options
 --------------------
 
-.. option:: -fatal-assembler-warnings
-
-  Treat all compiler warnings as errors.
-
 .. option:: -help
 
   Displays tool usage instructions and command line options.
@@ -79,6 +75,17 @@
   The meaning of risk is handled differently for each transform. See
   :ref:`transform documentation <transforms>` for details.
 
+.. option:: -final-syntax-check
+ 
+  After applying the final transform to a file, parse the file to ensure the
+  last transform did not introduce syntax errors. Syntax errors introduced by
+  earlier transforms are already caught when subsequent transforms parse the
+  file.
+
+.. option:: -fatal-assembler-warnings
+
+  Treat all compiler warnings as errors.
+
 
 .. option:: -version