Wdeprecated: StoredDiagnostics are stored in a SmallVector, so make sure they're copy/movable

Removing the no-op dtor makes these objects safely implicitly
copyable/movable/etc.

(& tidy up the ctor, while I'm here)

llvm-svn: 244971

clang/include/clang/Basic/Diagnostic.h

@@ -1264,7 +1264,7 @@ class StoredDiagnostic {
   std::vector<FixItHint> FixIts;
 
 public:
-  StoredDiagnostic();
+  StoredDiagnostic() = default;
   StoredDiagnostic(DiagnosticsEngine::Level Level, const Diagnostic &Info);
   StoredDiagnostic(DiagnosticsEngine::Level Level, unsigned ID, 
                    StringRef Message);
@@ -1272,7 +1272,6 @@ public:
                    StringRef Message, FullSourceLoc Loc,
                    ArrayRef<CharSourceRange> Ranges,
                    ArrayRef<FixItHint> Fixits);
-  ~StoredDiagnostic();
 
   /// \brief Evaluates true when this object stores a diagnostic.
   explicit operator bool() const { return Message.size() > 0; }

clang/lib/Basic/Diagnostic.cpp

@@ -945,8 +945,6 @@ FormatDiagnostic(const char *DiagStr, const char *DiagEnd,
   OutStr.append(Tree.begin(), Tree.end());
 }
 
-StoredDiagnostic::StoredDiagnostic() { }
-
 StoredDiagnostic::StoredDiagnostic(DiagnosticsEngine::Level Level, unsigned ID,
                                    StringRef Message)
   : ID(ID), Level(Level), Loc(), Message(Message) { }
@@ -975,8 +973,6 @@ StoredDiagnostic::StoredDiagnostic(DiagnosticsEngine::Level Level, unsigned ID,
 {
 }
 
-StoredDiagnostic::~StoredDiagnostic() { }
-
 /// IncludeInDiagnosticCounts - This method (whose default implementation
 ///  returns true) indicates whether the diagnostics handled by this
 ///  DiagnosticConsumer should be included in the number of diagnostics