addressed PR feedback

Author: vladima

src/compiler/emitter.ts

@@ -4221,15 +4221,16 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
                     const isExported = getCombinedNodeFlags(node) & NodeFlags.Export;
                     if (languageVersion >= ScriptTarget.ES6 && (!isExported || modulekind === ModuleKind.ES6)) {
                         // emit ES6 destructuring only if target module is ES6 or variable is not exported
-                        // exported variables in CJS\AMD are prefixed with 'exports.' so result javascript { exports.toString } = 1; is illegal
+                        // exported variables in CJS/AMD are prefixed with 'exports.' so result javascript { exports.toString } = 1; is illegal
 
                         const isTopLevelDeclarationInSystemModule =
                             modulekind === ModuleKind.System &&
                             shouldHoistVariable(node, /*checkIfSourceFileLevelDecl*/true);
 
                         if (isTopLevelDeclarationInSystemModule) {
-                            // in System modules top level variables are hoisted 
-                            // so variable declarations with destructuring are turned into destructuring assignments
+                            // In System modules top level variables are hoisted
+                            // so variable declarations with destructuring are turned into destructuring assignments.
+                            // As a result, they will need parentheses to disambiguate object binding assignments from blocks.
                             write("(");
                         }