Use stack IR when emitting text format (#312)

src/glue/js/binaryen.d.ts

@@ -5,7 +5,9 @@
 declare namespace binaryen {
   class Module {
     constructor(ref: number);
+    runPasses(passes: string[]): void;
     emitText(): string;
+    emitStackIR(optimize?: boolean): string;
     emitAsmjs(): string;
   }
 }

src/glue/js/index.ts

@@ -14,7 +14,7 @@ import "./i64";
 import { Module } from "../../module";
 
 Module.prototype.toText = function(this: Module) {
-  return new binaryen.Module(this.ref).emitText();
+  return new binaryen.Module(this.ref).emitStackIR();
 };
 
 Module.prototype.toAsmjs = function(this: Module) {