refactor(compiler): Record sub-messages as belonging to root i18n blo…

…ck (#53209)

ICU sub-messages should be recorded as belonging to the message for the
root i18n block they are part of. This ensures that they still get
emitted even if they are nested in a child template.

PR Close #53209

packages/compiler-cli/test/compliance/test_cases/r3_view_compiler_i18n/icu_logic/TEST_CASES.json

@@ -178,7 +178,7 @@
           ]
         }
       ],
-      "skipForTemplatePipeline": true
+      "focusTest": true
     },
     {
       "description": "should handle icus with interpolations",

packages/compiler/src/template/pipeline/src/phases/extract_i18n_messages.ts

@@ -55,14 +55,18 @@ const LIST_DELIMITER = '|';
  * used in the final output.
  */
 export function extractI18nMessages(job: CompilationJob): void {
-  // Save the i18n context ops for later use.
+  // Save the i18n start and i18n context ops for later use.
   const i18nContexts = new Map<ir.XrefId, ir.I18nContextOp>();
+  const i18nBlocks = new Map<ir.XrefId, ir.I18nStartOp>();
   for (const unit of job.units) {
     for (const op of unit.create) {
       switch (op.kind) {
         case ir.OpKind.I18nContext:
           i18nContexts.set(op.xref, op);
           break;
+        case ir.OpKind.I18nStart:
+          i18nBlocks.set(op.xref, op);
+          break;
       }
     }
   }
@@ -94,7 +98,8 @@ export function extractI18nMessages(job: CompilationJob): void {
           if (i18nContext.contextKind === ir.I18nContextKind.Icu) {
             const subMessage = createI18nMessage(job, i18nContext, op.messagePlaceholder);
             unit.create.push(subMessage);
-            const parentMessage = i18nBlockMessages.get(i18nContext.i18nBlock);
+            const rootI18nId = i18nBlocks.get(i18nContext.i18nBlock)!.root;
+            const parentMessage = i18nBlockMessages.get(rootI18nId);
             parentMessage?.subMessages.push(subMessage.xref);
           }
           ir.OpList.remove<ir.CreateOp>(op);