Remove some old compat in .js files.

src/Benchfib.js

@@ -1,5 +1,4 @@
 define(["amber/boot", "amber_core/Kernel-Objects"], function($boot){"use strict";
-if(!("nilAsValue" in $boot))$boot.nilAsValue=$boot.nilAsReceiver;
 var $core=$boot.api,nil=$boot.nilAsValue,$nil=$boot.nilAsReceiver,$recv=$boot.asReceiver,$globals=$boot.globals;
 var $pkg = $core.addPackage("Benchfib");
 $pkg.innerEval = function (expr) { return eval(expr); };

src/Examples.js

@@ -1,5 +1,4 @@
 define(["amber/boot", "amber/web/Web"], function($boot){"use strict";
-if(!("nilAsValue" in $boot))$boot.nilAsValue=$boot.nilAsReceiver;
 var $core=$boot.api,nil=$boot.nilAsValue,$nil=$boot.nilAsReceiver,$recv=$boot.asReceiver,$globals=$boot.globals;
 var $pkg = $core.addPackage("Examples");
 $pkg.innerEval = function (expr) { return eval(expr); };

src/IDE.js

@@ -2,7 +2,6 @@
 require(["codemirror/lib/codemirror", "amber_core/Platform-Services", "codemirror/addon/hint/show-hint", "codemirror/mode/smalltalk/smalltalk", "css!amber/legacy/resources/amber", "css!codemirror/addon/hint/show-hint", "css!codemirror/lib/codemirror", "css!codemirror/theme/ambiance", "jquery-ui"]);
 //>>excludeEnd("imports");
 define(["amber/boot", "amber/web/Web", "amber_core/Kernel-Objects"], function($boot){"use strict";
-if(!("nilAsValue" in $boot))$boot.nilAsValue=$boot.nilAsReceiver;
 var $core=$boot.api,nil=$boot.nilAsValue,$nil=$boot.nilAsReceiver,$recv=$boot.asReceiver,$globals=$boot.globals;
 var $pkg = $core.addPackage("IDE");
 $pkg.innerEval = function (expr) { return eval(expr); };