Parse JSDoc comments for ES6 class constructors and methods

Fixes #6646

(cherry picked from commit 1b282cd)

Author: RyanCavanaugh

src/compiler/parser.ts

@@ -4778,7 +4778,7 @@ namespace ts {
             parseExpected(SyntaxKind.ConstructorKeyword);
             fillSignature(SyntaxKind.ColonToken, /*yieldContext*/ false, /*awaitContext*/ false, /*requireCompleteParameterList*/ false, node);
             node.body = parseFunctionBlockOrSemicolon(/*isGenerator*/ false, /*isAsync*/ false, Diagnostics.or_expected);
-            return finishNode(node);
+            return addJSDocComment(finishNode(node));
         }
 
         function parseMethodDeclaration(fullStart: number, decorators: NodeArray<Decorator>, modifiers: ModifiersArray, asteriskToken: Node, name: PropertyName, questionToken: Node, diagnosticMessage?: DiagnosticMessage): MethodDeclaration {
@@ -4792,7 +4792,7 @@ namespace ts {
             const isAsync = !!(method.flags & NodeFlags.Async);
             fillSignature(SyntaxKind.ColonToken, /*yieldContext*/ isGenerator, /*awaitContext*/ isAsync, /*requireCompleteParameterList*/ false, method);
             method.body = parseFunctionBlockOrSemicolon(isGenerator, isAsync, diagnosticMessage);
-            return finishNode(method);
+            return addJSDocComment(finishNode(method));
         }
 
         function parsePropertyDeclaration(fullStart: number, decorators: NodeArray<Decorator>, modifiers: ModifiersArray, name: PropertyName, questionToken: Node): ClassElement {

tests/cases/fourslash/getJavaScriptCompletions16.ts

@@ -0,0 +1,18 @@
+/// <reference path="fourslash.ts" />
+
+// @allowNonTsExtensions: true
+// @Filename: file.js
+//// "use strict";
+//// 
+//// class Something {
+//// 
+////     /**
+////      * @param {number} a
+////      */
+////     constructor(a, b) {
+////         a./**/
+////     }
+//// }
+
+goTo.marker();
+verify.completionListContains('toFixed', undefined, undefined, 'method');