Clean up worker.js a bit (#9018)

Removed unused functions/vars, terminated unterminated statements,

* Changed const to var

* Change "this.err" to "var err"

* tempDoublePtr should only be available in !MODULARIZE

Author: VirtualTim

src/worker.js

@@ -11,7 +11,7 @@
 var threadInfoStruct = 0; // Info area for this thread in Emscripten HEAP (shared). If zero, this worker is not currently hosting an executing pthread.
 var selfThreadId = 0; // The ID of this thread. 0 if not hosting a pthread.
 var parentThreadId = 0; // The ID of the parent pthread that launched this thread.
-#if !WASM_BACKEND
+#if !WASM_BACKEND && !MODULARIZE
 var tempDoublePtr = 0; // A temporary memory area for global float and double marshalling operations.
 #endif
 
@@ -59,10 +59,6 @@ this.addEventListener('error', function(e) {
   console.error(e.error);
 });
 
-function threadPrint() {
-  var text = Array.prototype.slice.call(arguments).join(' ');
-  console.log(text);
-}
 function threadPrintErr() {
   var text = Array.prototype.slice.call(arguments).join(' ');
   console.error(text);
@@ -72,20 +68,19 @@ function threadAlert() {
   var text = Array.prototype.slice.call(arguments).join(' ');
   postMessage({cmd: 'alert', text: text, threadId: selfThreadId});
 }
-out = threadPrint;
-err = threadPrintErr;
+var err = threadPrintErr;
 this.alert = threadAlert;
 
 #if WASM
 Module['instantiateWasm'] = function(info, receiveInstance) {
   // Instantiate from the module posted from the main thread.
   // We can just use sync instantiation in the worker.
-  instance = new WebAssembly.Instance(wasmModule, info);
+  var instance = new WebAssembly.Instance(wasmModule, info);
   // We don't need the module anymore; new threads will be spawned from the main thread.
   wasmModule = null;
   receiveInstance(instance); // The second 'module' parameter is intentionally null here, we don't need to keep a ref to the Module object from here.
   return instance.exports;
-}
+};
 #endif
 
 var wasmModule;
@@ -275,4 +270,4 @@ this.onmessage = function(e) {
     console.error(e.stack);
     throw e;
   }
-}
+};