[analyzer] Minor improvements to region printing

[NoQ]

lib/StaticAnalyzer/Core/ExprEngine.cpp

2485

Irrelevant but i approve.

lib/StaticAnalyzer/Core/MemRegion.cpp

433

I feel that <= might look better.

[george.karpenkov]

lib/StaticAnalyzer/Core/MemRegion.cpp

433

but that's "less-than-or-equals"

[NoQ]

lib/StaticAnalyzer/Core/MemRegion.cpp

433

Hmm right.

lib/StaticAnalyzer/Core/ExprEngine.cpp

   const LocationContext *LCtx = Pred->getLocationContext();
 
   if (const auto *VD = dyn_cast<VarDecl>(D)) {
     // C permits "extern void v", and if you cast the address to a valid type,
     // you can even do things with it. We simply pretend
     assert(Ex->isGLValue() || VD->getType()->isVoidType());
     const LocationContext *LocCtxt = Pred->getLocationContext();
     const Decl *D = LocCtxt->getDecl();
-    const auto *MD = D ? dyn_cast<CXXMethodDecl>(D) : nullptr;
+    const auto *MD = dyn_cast_or_null<CXXMethodDecl>(D);
     const auto *DeclRefEx = dyn_cast<DeclRefExpr>(Ex);
     Optional<std::pair<SVal, QualType>> VInfo;
 
     if (AMgr.options.shouldInlineLambdas() && DeclRefEx &&
         DeclRefEx->refersToEnclosingVariableOrCapture() && MD &&
         MD->getParent()->isLambda()) {
       // Lookup the field of the lambda.
       const CXXRecordDecl *CXXRec = MD->getParent();

lib/StaticAnalyzer/Core/MemRegion.cpp

 }
 
 void BlockDataRegion::dumpToStream(raw_ostream &os) const {
   os << "block_data{" << BC;
   os << "; ";
   for (BlockDataRegion::referenced_vars_iterator
          I = referenced_vars_begin(),
          E = referenced_vars_end(); I != E; ++I)
-    os << "(" << I.getCapturedRegion() << "," <<
+    os << "(" << I.getCapturedRegion() << "<-" <<
                  I.getOriginalRegion() << ") ";
   os << '}';
 }
 
 void CompoundLiteralRegion::dumpToStream(raw_ostream &os) const {
   // FIXME: More elaborate pretty-printing.
   os << "{ " << static_cast<const void*>(CL) <<  " }";
 }

 
 void SymbolicRegion::dumpToStream(raw_ostream &os) const {
   if (isa<HeapSpaceRegion>(getSuperRegion()))
     os << "Heap";
   os << "SymRegion{" << sym << '}';
 }
 
 void VarRegion::dumpToStream(raw_ostream &os) const {
-  os << *cast<VarDecl>(D);
+  const auto *VD = cast<VarDecl>(D);
+  if (const auto *ID = VD->getIdentifier()) {
+    os << ID->getName();
+  } else {
+    os << "VarRegion{" << static_cast<const void*>(this) << '}';
+  }
 }
 
 LLVM_DUMP_METHOD void RegionRawOffset::dump() const {
   dumpToStream(llvm::errs());
 }
 
 void RegionRawOffset::dumpToStream(raw_ostream &os) const {
   os << "raw_offset{" << getRegion() << ',' << getOffset().getQuantity() << '}';