[analyzer] Drop the logic for collapsing the state if it's same as in preds.

One of the first attempts to reduce the size of the exploded graph dumps
was to skip the state dump as long as the state is the same as in all of
the predecessor nodes. With all the new facilities in place (node joining,
diff dumps), this feature doesn't do much, and when it does,
it's more harmful than useful. Let's remove it.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@375280 91177308-0d34-0410-b5e6-96231b3b80d8

Author: haoNoQ

lib/StaticAnalyzer/Core/ExprEngine.cpp

@@ -3083,16 +3083,7 @@ struct DOTGraphTraits<ExplodedGraph*> : public DefaultDOTGraphTraits {
     Out << "\\l"; // Adds a new-line to the last program point.
     Indent(Out, Space, IsDot) << "],\\l";
 
-    bool SameAsAllPredecessors =
-        std::all_of(N->pred_begin(), N->pred_end(), [&](const ExplodedNode *P) {
-          return P->getState() == State;
-        });
-
-    if (!SameAsAllPredecessors) {
-      State->printDOT(Out, N->getLocationContext(), Space);
-    } else {
-      Indent(Out, Space, IsDot) << "\"program_state\": null";
-    }
+    State->printDOT(Out, N->getLocationContext(), Space);
 
     Out << "\\l}\\l";
     return Out.str();

test/Analysis/dump_egraph.c

@@ -48,3 +48,5 @@ int foo() {
 // CHECK: \"pretty\": \"'\\\\x13'\"
 
 // CHECK: \"has_report\": 1
+
+// CHECK-NOT: \"program_state\": null