Add KillStruct to region store.  
 - put the killed region in the kill set.
 - set its default value to unknown.
 - removes all bindings for its subregions.  


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62138 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Analysis/array-struct.c b/test/Analysis/array-struct.c
index dd43a6d..8f4bb04 100644
--- a/test/Analysis/array-struct.c
+++ b/test/Analysis/array-struct.c
@@ -46,6 +46,7 @@
 }
 
 // Struct variable in lvalue context.
+// Assign UnknownVal to the whole struct.
 void f5() {
   struct s data;
   g1(&data);