Add _Platform_export

Rather than having the compiler generate this code, it just calls this
function. This means we can modify the behavior of exports with
releases of core rather than new compiler releases.

I also code golfed this from what was in the compiler so it is a decent
bit smaller.

src/Elm/Kernel/Platform.js

@@ -13,9 +13,9 @@ import Elm.Kernel.Utils exposing (Tuple0)
 // PROGRAMS
 
 
-var _Platform_worker = F4(function(impl, flagDecoder, object, debugMetadata)
+var _Platform_worker = F4(function(impl, flagDecoder, debugMetadata, object)
 {
-	object['worker'] = function worker(flags)
+	object['worker'] = function(flags)
 	{
 		return _Platform_initialize(
 			flagDecoder,
@@ -437,3 +437,65 @@ function _Platform_setupIncomingPort(name, sendToApp)
 
 	return { send: send };
 }
+
+
+
+// EXPORT ELM MODULES
+//
+// Have DEBUG and PROD versions so that we can (1) give nicer errors in
+// debug mode and (2) not pay for the bits needed for that in prod mode.
+//
+
+
+function _Platform_export__PROD(exports)
+{
+	(typeof define === 'function' && define['amd'])
+		? define([], function() { return exports; })
+		:
+	(typeof module === 'object')
+		? module['exports'] = exports
+		:
+	scope['Elm']
+		? _Platform_mergeExportsProd(scope['Elm'], exports)
+		: scope['Elm'] = exports;
+}
+
+
+function _Platform_mergeExportsProd(obj, exports)
+{
+	for (var name in exports)
+	{
+		(name in obj)
+			? (typeof name === 'function')
+				? __Error_throw(6)
+				: _Platform_mergeExportsProd(obj[name], exports[name])
+			: (obj[name] = exports[name]);
+	}
+}
+
+
+function _Platform_export__DEBUG(exports)
+{
+	(typeof define === 'function' && define['amd'])
+		? define([], function() { return exports; })
+		:
+	(typeof module === 'object')
+		? module['exports'] = exports
+		:
+	scope['Elm']
+		? _Platform_mergeExportsDebug('Elm', scope['Elm'], exports)
+		: scope['Elm'] = exports;
+}
+
+
+function _Platform_mergeExportsDebug(moduleName, obj, exports)
+{
+	for (var name in exports)
+	{
+		(name in obj)
+			? (typeof name === 'function')
+				? __Error_throw(6, moduleName)
+				: _Platform_mergeExportsDebug(moduleName + '.' + name, obj[name], exports[name])
+			: (obj[name] = exports[name]);
+	}
+}