[analyzer] Fix static code analysis concerns

[Manna]

Summary

ProcessMemberDtor(), ProcessDeleteDtor(), and ProcessAutomaticObjDtor():
Fix static analyzer warnings with suspicious dereference of pointer 'Pred' in function call before NULL checks - NFCI

[Manna]

Thank you for the reviews!

[Manna]

@Gábor Horváth or @Domján Dániel, could you please commit the patch?

Thanks,
Soumi Manna
Email address: [e-mail]

clang/lib/StaticAnalyzer/Core/ExprEngine.cpp

Region = makeElementRegion(state, loc::MemRegionVal(Region), varType,
                .getAsRegion();
 
   NodeBuilder Bldr(Pred, Dst, getBuilderContext());
 
   static SimpleProgramPointTag PT("ExprEngine",
                                   "Prepare for object destruction");
   PreImplicitCall PP(DtorDecl, varDecl->getLocation(), LCtx, &PT);
   Pred = Bldr.generateNode(PP, state, Pred);
-  Bldr.takeNodes(Pred);
 
   if (!Pred)
     return;
+  Bldr.takeNodes(Pred);
 
   VisitCXXDestructor(varType, Region, Dtor.getTriggerStmt(),
                      /*IsBase=*/false, Pred, Dst, CallOpts);
 }
 
 void ExprEngine::ProcessDeleteDtor(const CFGDeleteDtor Dtor,
                                    ExplodedNode *Pred,
                                    ExplodedNodeSet &Dst) {
if (ArgR)
                  .getAsRegion();
   }
 
   NodeBuilder Bldr(Pred, Dst, getBuilderContext());
   static SimpleProgramPointTag PT("ExprEngine",
                                   "Prepare for object destruction");
   PreImplicitCall PP(getDtorDecl(DTy), DE->getBeginLoc(), LCtx, &PT);
   Pred = Bldr.generateNode(PP, State, Pred);
-  Bldr.takeNodes(Pred);
 
   if (!Pred)
     return;
+  Bldr.takeNodes(Pred);
 
   VisitCXXDestructor(DTy, ArgR, DE, /*IsBase=*/false, Pred, Dst, CallOpts);
 }
 
 void ExprEngine::ProcessBaseDtor(const CFGBaseDtor D,
                                  ExplodedNode *Pred, ExplodedNodeSet &Dst) {
   const LocationContext *LCtx = Pred->getLocationContext();
 
FieldVal =
       makeElementRegion(State, FieldVal, T, CallOpts.IsArrayCtorOrDtor, Idx);
 
   NodeBuilder Bldr(Pred, Dst, getBuilderContext());
 
   static SimpleProgramPointTag PT("ExprEngine",
                                   "Prepare for object destruction");
   PreImplicitCall PP(DtorDecl, Member->getLocation(), LCtx, &PT);
   Pred = Bldr.generateNode(PP, State, Pred);
-  Bldr.takeNodes(Pred);
 
   if (!Pred)
     return;
+  Bldr.takeNodes(Pred);
 
   VisitCXXDestructor(T, FieldVal.getAsRegion(), CurDtor->getBody(),
                      /*IsBase=*/false, Pred, Dst, CallOpts);
 }
 
 void ExprEngine::ProcessTemporaryDtor(const CFGTemporaryDtor D,
                                       ExplodedNode *Pred,
                                       ExplodedNodeSet &Dst) {