[BUGFIX lts] Ensures that computed can depend on dynamic hash keys

Ensures that computeds can depend on dynamic hash keys that did not
exist on the original hash.

(cherry picked from commit 628a928)

package.json

@@ -51,7 +51,7 @@
     "@babel/plugin-transform-block-scoping": "^7.8.3",
     "@babel/plugin-transform-object-assign": "^7.8.3",
     "@ember/edition-utils": "^1.2.0",
-    "@glimmer/vm-babel-plugins": "0.79.2",
+    "@glimmer/vm-babel-plugins": "0.79.3",
     "babel-plugin-debug-macros": "^0.3.3",
     "babel-plugin-filter-imports": "^4.0.0",
     "broccoli-concat": "^4.2.4",
@@ -76,19 +76,19 @@
   },
   "devDependencies": {
     "@babel/preset-env": "^7.9.5",
-    "@glimmer/compiler": "0.79.2",
-    "@glimmer/destroyable": "0.79.2",
+    "@glimmer/compiler": "0.79.3",
+    "@glimmer/destroyable": "0.79.3",
     "@glimmer/env": "^0.1.7",
-    "@glimmer/global-context": "0.79.2",
-    "@glimmer/interfaces": "0.79.2",
-    "@glimmer/manager": "0.79.2",
-    "@glimmer/node": "0.79.2",
-    "@glimmer/opcode-compiler": "0.79.2",
-    "@glimmer/owner": "0.79.2",
-    "@glimmer/program": "0.79.2",
-    "@glimmer/reference": "0.79.2",
-    "@glimmer/runtime": "0.79.2",
-    "@glimmer/validator": "0.79.2",
+    "@glimmer/global-context": "0.79.3",
+    "@glimmer/interfaces": "0.79.3",
+    "@glimmer/manager": "0.79.3",
+    "@glimmer/node": "0.79.3",
+    "@glimmer/opcode-compiler": "0.79.3",
+    "@glimmer/owner": "0.79.3",
+    "@glimmer/program": "0.79.3",
+    "@glimmer/reference": "0.79.3",
+    "@glimmer/runtime": "0.79.3",
+    "@glimmer/validator": "0.79.3",
     "@simple-dom/document": "^1.4.0",
     "@types/qunit": "^2.9.1",
     "@types/rsvp": "^4.0.3",

packages/@ember/-internals/glimmer/tests/integration/helpers/hash-test.js

@@ -219,6 +219,60 @@ moduleFor(
       this.assertText('Godfrey Chan');
     }
 
+    ['@test works with computeds on non-defined properties']() {
+      let instance;
+
+      let FooBarComponent = Component.extend({
+        init() {
+          this._super(...arguments);
+
+          if (HAS_NATIVE_PROXY) {
+            expectDeprecation(() => {
+              set(this.hash, 'lastName', 'Hietala');
+            }, /You set the '.*' property on a {{hash}} object/);
+          } else {
+            set(this.hash, 'lastName', 'Hietala');
+          }
+
+          instance = this;
+        },
+
+        fullName: computed('hash.firstName', 'hash.lastName', function () {
+          return `${this.hash.firstName} ${this.hash.lastName}`;
+        }),
+      });
+
+      this.registerComponent('foo-bar', {
+        ComponentClass: FooBarComponent,
+        template: `{{this.fullName}}`,
+      });
+
+      this.render(`{{foo-bar hash=(hash firstName=this.firstName)}}`, {
+        firstName: 'Chad',
+        lastName: 'Hietala',
+      });
+
+      this.assertText('Chad Hietala');
+
+      runTask(() => this.rerender());
+
+      this.assertText('Chad Hietala');
+
+      runTask(() => {
+        set(this.context, 'firstName', 'Godfrey');
+
+        if (HAS_NATIVE_PROXY) {
+          expectDeprecation(() => {
+            set(instance.hash, 'lastName', 'Chan');
+          }, /You set the '.*' property on a {{hash}} object/);
+        } else {
+          set(instance.hash, 'lastName', 'Chan');
+        }
+      });
+
+      this.assertText('Godfrey Chan');
+    }
+
     ['@test works when properties are set dynamically']() {
       let fooBarInstance;
       let FooBarComponent = Component.extend({