Mark returnFlowNode property as internal

Author: ahejlsberg

src/compiler/types.ts

@@ -929,7 +929,7 @@ namespace ts {
         kind: SyntaxKind.Constructor;
         parent?: ClassDeclaration | ClassExpression;
         body?: FunctionBody;
-        returnFlowNode?: FlowNode;
+        /* @internal */ returnFlowNode?: FlowNode;
     }
 
     /** For when we encounter a semicolon in a class declaration. ES6 allows these as class elements. */
@@ -3809,6 +3809,7 @@ namespace ts {
         strict?: boolean;
         strictFunctionTypes?: boolean;  // Always combine with strict property
         strictNullChecks?: boolean;  // Always combine with strict property
+        strictPropertyInitialization?: boolean;  // Always combine with strict property
         /* @internal */ stripInternal?: boolean;
         suppressExcessPropertyErrors?: boolean;
         suppressImplicitAnyIndexErrors?: boolean;