perf(ivy): add self-closing elementContainer instruction (#31444)

Adds a new `elementContainer` instruction that can be used to avoid two instruction (`elementContainerStart` and `elementContainerEnd`) for `ng-container` that has text-only content. This is particularly useful when we have `ng-container` inside i18n sections.

This PR resolves FW-1105.

PR Close #31444

packages/core/src/core_render3_private_export.ts

@@ -118,6 +118,7 @@ export {
   ɵɵallocHostVars,
   ɵɵelementContainerStart,
   ɵɵelementContainerEnd,
+  ɵɵelementContainer,
   ɵɵstyling,
   ɵɵstyleMap,
   ɵɵclassMap,

packages/core/src/render3/index.ts

@@ -56,6 +56,7 @@ export {
   ɵɵdirectiveInject,
 
   ɵɵelement,
+  ɵɵelementContainer,
   ɵɵelementContainerEnd,
 
   ɵɵelementContainerStart,

packages/core/src/render3/instructions/element_container.ts

@@ -100,3 +100,19 @@ export function ɵɵelementContainerEnd(): void {
 
   registerPostOrderHooks(tView, previousOrParentTNode);
 }
+
+/**
+ * Creates an empty logical container using {@link elementContainerStart}
+ * and {@link elementContainerEnd}
+ *
+ * @param index Index of the element in the LView array
+ * @param attrs Set of attributes to be used when matching directives.
+ * @param localRefs A set of local reference bindings on the element.
+ *
+ * @codeGenApi
+ */
+export function ɵɵelementContainer(
+    index: number, attrs?: TAttributes | null, localRefs?: string[] | null): void {
+  ɵɵelementContainerStart(index, attrs, localRefs);
+  ɵɵelementContainerEnd();
+}

packages/core/src/render3/jit/environment.ts

@@ -61,6 +61,7 @@ export const angularCoreEnv: {[name: string]: Function} =
        'ɵɵelement': r3.ɵɵelement,
        'ɵɵelementContainerStart': r3.ɵɵelementContainerStart,
        'ɵɵelementContainerEnd': r3.ɵɵelementContainerEnd,
+       'ɵɵelementContainer': r3.ɵɵelementContainer,
        'ɵɵpureFunction0': r3.ɵɵpureFunction0,
        'ɵɵpureFunction1': r3.ɵɵpureFunction1,
        'ɵɵpureFunction2': r3.ɵɵpureFunction2,