Adding missing @module to several fourslash tests

tests/cases/fourslash/getEmitOutputSingleFile2.ts

@@ -1,6 +1,7 @@
 /// <reference path="fourslash.ts" />
 
 // @BaselineFile: getEmitOutputSingleFile2.baseline
+// @module: CommonJS
 // @declaration: true
 // @out: declSingleFile.js
 // @outDir: tests/cases/fourslash/

tests/cases/fourslash/getEmitOutputWithDeclarationFile2.ts

@@ -1,6 +1,7 @@
 /// <reference path="fourslash.ts" />
 
 // @BaselineFile: getEmitOutputWithDeclarationFile2.baseline
+// @module: CommonJS
 
 // @Filename: decl.d.ts
 // @emitThisFile: true

tests/cases/fourslash/getSemanticDiagnosticForDeclaration.ts

@@ -1,5 +1,6 @@
 /// <reference path="fourslash.ts" />
 
+// @module: CommonJS
 // @declaration: true
 //// interface privateInterface {}
 //// export class Bar implements /*1*/privateInterface/*2*/{ }

tests/cases/fourslash/getSemanticDiagnosticForNoDeclaration.ts

@@ -1,5 +1,7 @@
 /// <reference path="fourslash.ts" />
 
+// @module: CommonJS
+
 //// interface privateInterface {}
 //// export class Bar implements /*1*/privateInterface/*2*/{ }
 

tests/cases/fourslash/underscoreTyping1.ts

@@ -1,4 +1,6 @@
 /// <reference path="fourslash.ts" />
+
+// @module: CommonJS
 
 //// interface Dictionary<T> {
 ////     [x: string]: T;