Merge NullDerefChecker.[h,cpp] and UndefDerefChecker.[h,cpp].  They are essentially two parts of the same check.

llvm-svn: 85911
diff --git a/clang/lib/Analysis/GRExprEngineInternalChecks.cpp b/clang/lib/Analysis/GRExprEngineInternalChecks.cpp
index 089d25d..23ef288 100644
--- a/clang/lib/Analysis/GRExprEngineInternalChecks.cpp
+++ b/clang/lib/Analysis/GRExprEngineInternalChecks.cpp
@@ -15,8 +15,7 @@
 #include "clang/Analysis/PathSensitive/BugReporter.h"
 #include "clang/Analysis/PathSensitive/GRExprEngine.h"
 #include "clang/Analysis/PathSensitive/CheckerVisitor.h"
-#include "clang/Analysis/PathSensitive/Checkers/NullDerefChecker.h"
-#include "clang/Analysis/PathSensitive/Checkers/UndefDerefChecker.h"
+#include "clang/Analysis/PathSensitive/Checkers/DereferenceChecker.h"
 #include "clang/Analysis/PathSensitive/Checkers/DivZeroChecker.h"
 #include "clang/Analysis/PathSensitive/Checkers/BadCallChecker.h"
 #include "clang/Analysis/PathSensitive/Checkers/UndefinedArgChecker.h"