Angular: Support @content block (#19431)

changelog_unreleased/angular/19431.md

@@ -0,0 +1,29 @@
+#### Support `@content` block (#19431 by @fisker)
+
+<!-- prettier-ignore -->
+```html
+<!-- Input -->
+<FancyButton [label]="title">
+  @content(icon) {
+    <span>Icon</span>
+  }
+  @content(description) {
+    <span>Description text</span>
+  }
+  <span>Other children</span>
+</FancyButton>
+
+<!-- Prettier stable -->
+SyntaxError: Unexpected character "EOF" (Do you have an unescaped "{" in your template? Use "{{ '{' }}") to escape it.) (9:15)
+
+<!-- Prettier main -->
+<FancyButton [label]="title">
+  @content(icon) {
+    <span>Icon!</span>
+  }
+  @content(description) {
+    <span>Description text</span>
+  }
+  <span>Other children</span>
+</FancyButton>
+```