lit: Add 'valgrind' and 'valgrind-leaks' features when valgrind is used.
 - These can be used with the XFAIL options.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166303 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/CommandGuide/lit.rst b/docs/CommandGuide/lit.rst
index 3eb0be9..841bd20 100644
--- a/docs/CommandGuide/lit.rst
+++ b/docs/CommandGuide/lit.rst
@@ -125,6 +125,10 @@
  *--error-exitcode* argument for valgrind is used so that valgrind failures will
  cause the program to exit with a non-zero status.
 
+ When this option is enabled, **lit** will also automatically provide a
+ "valgrind" feature that can be used to conditionally disable (or expect failure
+ in) certain tests.
+
 
 
 **--vg-arg**\ =\ *ARG*
@@ -133,6 +137,15 @@
 
 
 
+**--vg-leak**
+
+ When *--vg* is used, enable memory leak checks. When this option is enabled,
+ **lit** will also automatically provide a "valgrind-leaks" feature that can be
+ used to conditionally disable (or expect failure in) certain tests.
+
+
+
+
 **--time-tests**
 
  Track the wall time individual tests take to execute and includes the results in