Document the -input-file option of FileCheck



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167517 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/CommandGuide/FileCheck.rst b/docs/CommandGuide/FileCheck.rst
index 51a9bf6..6fdc175 100644
--- a/docs/CommandGuide/FileCheck.rst
+++ b/docs/CommandGuide/FileCheck.rst
@@ -45,6 +45,11 @@
 
 
 
+**--input-file** *filename*
+
+  File to check (defaults to stdin).
+
+
 **--strict-whitespace**
 
  By default, FileCheck canonicalizes input horizontal whitespace (spaces and