Issue 23018. Fix for inlining multiline strings with leading whitespaces.

pkg/analyzer/test/generated/ast_test.dart

Index: pkg/analyzer/test/generated/ast_test.dart
diff --git a/pkg/analyzer/test/generated/ast_test.dart b/pkg/analyzer/test/generated/ast_test.dart
index 535c75b68eef4e64a30ae948d8329ceee330e474..ef6ed1673f8a5aaba0bea34353f80a933e6257ad 100644
--- a/pkg/analyzer/test/generated/ast_test.dart
+++ b/pkg/analyzer/test/generated/ast_test.dart
@@ -1305,6 +1305,11 @@ class SimpleStringLiteralTest extends ParserTestCase {
         TokenFactory.tokenFromString("r\"\"\"X\"\"\""), "X").contentsOffset, 4);
     expect(new SimpleStringLiteral(
         TokenFactory.tokenFromString("r'''X'''"), "X").contentsOffset, 4);
+    // leading whitespace
+    expect(new SimpleStringLiteral(
+        TokenFactory.tokenFromString("''' \ \nX''"), "X").contentsOffset, 6);
+    expect(new SimpleStringLiteral(
+        TokenFactory.tokenFromString('r""" \ \nX"""'), "X").contentsOffset, 7);
   }
 
   void test_isMultiline() {