Clean up the Checker API a little more, resolving some hidden bugs
along the way.  Important changes:

1) To generate a sink node, use GenerateSink(); GenerateNode() is for
generating regular transitions.  This makes the API clearer and also
allows us to use the 'bool' option to GenerateNode() for a different
purpose.

2) GenerateNode() now automatically adds the generated node to the
destination ExplodedNodeSet (autotransition) unless the client
specifies otherwise with a bool flag.  Several checkers did not call
'addTransition()' after calling 'GenerateNode()', causing the
simulation path to be prematurely culled when a non-fail stop bug was
encountered.

3) Add variants of GenerateNode()/GenerateSink() that take neither a
Stmt* or a GRState*; most callers of GenerateNode() just pass in the
same Stmt* as provided when the CheckerContext object is created; we
can just use that the majority of the time.  This cleanup also allows
us to potentially coelesce the APIs for evaluating branches and
end-of-paths (which currently directly use builders).

4) addTransition() no longer needs to be called except for a few
cases.  We now have a variant of addTransition() that takes a
GRState*; this allows one to propagate the updated state without
caring about generating a new node explicitly.  This nicely cleaned up
a bunch of cases that called autoTransition() with a bunch of
conditional logic surround the call (that common logic has now been
swallowed up by addTransition() itself).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@89707 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/UndefinedArraySubscriptChecker.cpp b/lib/Analysis/UndefinedArraySubscriptChecker.cpp
index 887c775..3ae0c57 100644
--- a/lib/Analysis/UndefinedArraySubscriptChecker.cpp
+++ b/lib/Analysis/UndefinedArraySubscriptChecker.cpp
@@ -41,7 +41,7 @@
 UndefinedArraySubscriptChecker::PreVisitArraySubscriptExpr(CheckerContext &C, 
                                                 const ArraySubscriptExpr *A) {
   if (C.getState()->getSVal(A->getIdx()).isUndef()) {
-    if (ExplodedNode *N = C.GenerateNode(A, true)) {
+    if (ExplodedNode *N = C.GenerateSink()) {
       if (!BT)
         BT = new BuiltinBug("Array subscript is undefined");