Fix clang-6 strictness surrounding virtual destructors

Reviewed By: smeenai

Differential Revision: D7326765

fbshipit-source-id: 9df477dfa89812e05e79b5e6d510bcbbc793381c

ReactCommon/exceptions/ExceptionManager.h

@@ -16,6 +16,8 @@ namespace react {
  */
 class ExceptionManager {
 public:
+  virtual ~ExceptionManager() = default;
+
   virtual void handleSoftException(const std::exception &e) const = 0;
   virtual void handleFatalException(const std::exception &e) const = 0;
 };

ReactCommon/fabric/core/componentdescriptor/ComponentDescriptor.h

@@ -26,6 +26,8 @@ using SharedComponentDescriptor = std::shared_ptr<ComponentDescriptor>;
 class ComponentDescriptor {
 public:
 
+  virtual ~ComponentDescriptor() = default;
+
   /*
    * Returns `componentHandle` associated with particular kind of components.
    * All `ShadowNode`s of this type must return same `componentHandle`.

ReactCommon/fabric/core/shadownode/Props.h

@@ -28,6 +28,8 @@ class Props:
   public virtual DebugStringConvertible {
 
 public:
+  virtual ~Props() = default;
+
   virtual void apply(const RawProps &rawProps);
 
 private:

ReactCommon/fabric/debug/DebugStringConvertible.h

@@ -31,6 +31,8 @@ struct DebugStringConvertibleOptions {
 class DebugStringConvertible {
 
 public:
+  virtual ~DebugStringConvertible() = default;
+
   // Returns a name of the object.
   // Default implementation returns "Node".
   virtual std::string getDebugName() const;