Add comments to test.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@84078 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Analysis/casts.c b/test/Analysis/casts.c
index 19ea6af..ae51ffb 100644
--- a/test/Analysis/casts.c
+++ b/test/Analysis/casts.c
@@ -30,9 +30,9 @@
   int *tbool = ((void*)0);
   struct s *t = *pval;
   pval = &(t->value);
-  tbool = (int *)pval; // Should record the cast-to type here.
+  tbool = (int *)pval; // use the cast-to type 'int *' to create element region.
   char c = (unsigned char) *tbool; // Should use cast-to type to create symbol.
-  if (*tbool == -1)
+  if (*tbool == -1) // here load the element region with the correct type 'int'
     (void)3;
 }