Rework checker "packages" and groups to be more hierarchical.

llvm-svn: 128187
diff --git a/clang/test/Analysis/undef-buffers.c b/clang/test/Analysis/undef-buffers.c
index 7ab1476..df124b1 100644
--- a/clang/test/Analysis/undef-buffers.c
+++ b/clang/test/Analysis/undef-buffers.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -analyze -analyzer-checker=core,core.experimental -analyzer-store=region -verify %s
+// RUN: %clang_cc1 -analyze -analyzer-checker=core,unix.experimental,core.uninitialized -analyzer-store=region -verify %s
 typedef __typeof(sizeof(int)) size_t;
 void *malloc(size_t);
 void free(void *);