add guard clause test

Author: raichoo

tests/indent/test019/expected.hs

@@ -0,0 +1,8 @@
+    foo x
+      | x == x = True
+
+      | 
+
+      ,
+
+      = 

tests/indent/test019/test.hs

@@ -0,0 +1,3 @@
+    foo x
+      | x == x = True
+

tests/indent/test019/test.vim

@@ -0,0 +1,3 @@
+Go| o,o= 
+:saveas! result.hs
+:q!