feat(ivy): add property instruction (#29513)

- Adds `property` instruction
- Does _NOT_ add compiler changes to accommodate `property` instruction, that will be a follow up PR.
- Updates `select` instruction to set the selected index in state.
- Adds dev mode assertions around the selected index state.

Related #29527

PR Close #29513

packages/core/src/render3/state.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {assertDefined} from '../util/assert';
+import {assertDefined, assertGreaterThan} from '../util/assert';
 
 import {assertLViewOrUndefined} from './assert';
 import {executeHooks} from './hooks';
@@ -340,3 +340,28 @@ export function leaveView(newView: LView): void {
   }
   enterView(newView, null);
 }
+
+let _selectedIndex = -1;
+
+/**
+ * Gets the most recent index passed to {@link select}
+ *
+ * Used with {@link property} instruction (and more in the future) to identify the index in the
+ * current `LView` to act on.
+ */
+export function getSelectedIndex() {
+  ngDevMode &&
+      assertGreaterThan(
+          _selectedIndex, -1, 'select() should be called prior to retrieving the selected index');
+  return _selectedIndex;
+}
+
+/**
+ * Sets the most recent index passed to {@link select}
+ *
+ * Used with {@link property} instruction (and more in the future) to identify the index in the
+ * current `LView` to act on.
+ */
+export function setSelectedIndex(index: number) {
+  _selectedIndex = index;
+}