[analyzer] Tidy up a few uses of Optional in RegionStore.

Some that I just added needed conversion to use 'None', others looked
better using Optional<SVal>::create.

No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175714 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Core/RegionStore.cpp b/lib/StaticAnalyzer/Core/RegionStore.cpp
index 09bbcef..310c080 100644
--- a/lib/StaticAnalyzer/Core/RegionStore.cpp
+++ b/lib/StaticAnalyzer/Core/RegionStore.cpp
@@ -225,9 +225,7 @@
 typedef const RegionBindingsRef& RegionBindingsConstRef;
 
 Optional<SVal> RegionBindingsRef::getDirectBinding(const MemRegion *R) const {
-  if (const SVal *V = lookup(R, BindingKey::Direct))
-    return *V;
-  return None;
+  return Optional<SVal>::create(lookup(R, BindingKey::Direct));
 }
 
 Optional<SVal> RegionBindingsRef::getDefaultBinding(const MemRegion *R) const {
@@ -235,9 +233,8 @@
     if (const TypedValueRegion *TR = dyn_cast<TypedValueRegion>(R))
       if (TR->getValueType()->isUnionType())
         return UnknownVal();
-  if (const SVal *V = lookup(R, BindingKey::Default))
-    return *V;
-  return None;
+
+  return Optional<SVal>::create(lookup(R, BindingKey::Default));
 }
 
 RegionBindingsRef RegionBindingsRef::addBinding(BindingKey K, SVal V) const {
@@ -1267,11 +1264,11 @@
                        const SubRegion *R, bool AllowSubregionBindings) {
   Optional<SVal> V = B.getDefaultBinding(R);
   if (!V)
-    return Optional<nonloc::LazyCompoundVal>();
+    return None;
 
   Optional<nonloc::LazyCompoundVal> LCV = V->getAs<nonloc::LazyCompoundVal>();
   if (!LCV)
-    return Optional<nonloc::LazyCompoundVal>();
+    return None;
 
   // If the LCV is for a subregion, the types won't match, and we shouldn't
   // reuse the binding. Unfortuately we can only check this if the destination
@@ -1280,7 +1277,7 @@
     QualType RegionTy = TVR->getValueType();
     QualType SourceRegionTy = LCV->getRegion()->getValueType();
     if (!SVB.getContext().hasSameUnqualifiedType(RegionTy, SourceRegionTy))
-      return Optional<nonloc::LazyCompoundVal>();
+      return None;
   }
 
   if (!AllowSubregionBindings) {
@@ -1290,7 +1287,7 @@
     collectSubRegionKeys(Keys, SVB, *B.lookup(R->getBaseRegion()), R,
                          /*IncludeAllDefaultBindings=*/true);
     if (Keys.size() > 1)
-      return Optional<nonloc::LazyCompoundVal>();
+      return None;
   }
 
   return *LCV;