[BUGFIX beta] Ensure {{on}} does not run in FastBoot / SSR contexts.

Since `{{on}}` is a "special" built-in modifier manager, the generic
fixes for custom modifier managers do not fix `on`. This applies the
same general fix, and ensures that `{{on}}` is a no-op in FastBoot mode.

packages/@ember/-internals/glimmer/lib/modifiers/on.ts

@@ -1,7 +1,7 @@
 import { assert } from '@ember/debug';
 import { DEBUG } from '@glimmer/env';
 import { Opaque, Simple } from '@glimmer/interfaces';
-import { Tag } from '@glimmer/reference';
+import { Tag, CONSTANT_TAG } from '@glimmer/reference';
 import { Arguments, CapturedArguments, ModifierManager } from '@glimmer/runtime';
 import { Destroyable } from '@glimmer/util';
 import buildUntouchableThis from '../utils/untouchable-this';
@@ -210,24 +210,37 @@ function addEventListener(
   }
 }
 
-export default class OnModifierManager implements ModifierManager<OnModifierState, Opaque> {
+export default class OnModifierManager implements ModifierManager<OnModifierState | null, Opaque> {
   public SUPPORTS_EVENT_OPTIONS: boolean = SUPPORTS_EVENT_OPTIONS;
+  public isInteractive: boolean;
+
+  constructor(isInteractive: boolean) {
+    this.isInteractive = isInteractive;
+  }
 
   get counters() {
     return { adds, removes };
   }
 
   create(element: Simple.Element | Element, _state: Opaque, args: Arguments) {
+    if (!this.isInteractive) { return null; }
+
     const capturedArgs = args.capture();
 
     return new OnModifierState(<Element>element, capturedArgs);
   }
 
-  getTag({ tag }: OnModifierState): Tag {
-    return tag;
+  getTag(state: OnModifierState | null): Tag {
+    if (state === null) { return CONSTANT_TAG; }
+
+    return state.tag;
   }
 
-  install(state: OnModifierState) {
+  install(state: OnModifierState | null) {
+    if (state === null) {
+      return;
+    }
+
     state.updateFromArgs();
 
     let { element, eventName, callback, options } = state;
@@ -237,7 +250,11 @@ export default class OnModifierManager implements ModifierManager<OnModifierStat
     state.shouldUpdate = false;
   }
 
-  update(state: OnModifierState) {
+  update(state: OnModifierState | null) {
+    if (state === null) {
+      return;
+    }
+
     // stash prior state for el.removeEventListener
     let { element, eventName, callback, options } = state;
 
@@ -256,7 +273,7 @@ export default class OnModifierManager implements ModifierManager<OnModifierStat
     state.shouldUpdate = false;
   }
 
-  getDestructor(state: Destroyable) {
+  getDestructor(state: Destroyable | null) {
     return state;
   }
 }

packages/@ember/-internals/glimmer/lib/resolver.ts

@@ -100,14 +100,7 @@ if (EMBER_GLIMMER_FN_HELPER) {
 interface IBuiltInModifiers {
   [name: string]: ModifierDefinition | undefined;
 }
-const BUILTIN_MODIFIERS: IBuiltInModifiers = {
-  action: { manager: new ActionModifierManager(), state: null },
-  on: undefined,
-};
 
-if (EMBER_GLIMMER_ON_MODIFIER) {
-  BUILTIN_MODIFIERS.on = { manager: new OnModifierManager(), state: null };
-}
 export default class RuntimeResolver implements IRuntimeResolver<OwnedTemplateMeta> {
   public isInteractive: boolean;
   public compiler: LazyCompiler<OwnedTemplateMeta>;
@@ -119,7 +112,7 @@ export default class RuntimeResolver implements IRuntimeResolver<OwnedTemplateMe
 
   private builtInHelpers: IBuiltInHelpers = BUILTINS_HELPERS;
 
-  private builtInModifiers: IBuiltInModifiers = BUILTIN_MODIFIERS;
+  private builtInModifiers: IBuiltInModifiers;
 
   // supports directly imported late bound layouts on component.prototype.layout
   private templateCache: Map<Owner, Map<TemplateFactory, OwnedTemplate>> = new Map();
@@ -136,6 +129,14 @@ export default class RuntimeResolver implements IRuntimeResolver<OwnedTemplateMe
     populateMacros(macros);
     this.compiler = new LazyCompiler<OwnedTemplateMeta>(new CompileTimeLookup(this), this, macros);
     this.isInteractive = isInteractive;
+
+    this.builtInModifiers = {
+      action: { manager: new ActionModifierManager(), state: null },
+    };
+
+    if (EMBER_GLIMMER_ON_MODIFIER) {
+      this.builtInModifiers.on = { manager: new OnModifierManager(isInteractive), state: null };
+    }
   }
 
   /***  IRuntimeResolver ***/