Fixes for AST summary generation when variables are missing.

pkg/analyzer/test/src/summary/summary_common.dart

Index: pkg/analyzer/test/src/summary/summary_common.dart
diff --git a/pkg/analyzer/test/src/summary/summary_common.dart b/pkg/analyzer/test/src/summary/summary_common.dart
index a0eb33433eb31df08a4d67979066535230ddf428..e6685d895e7bca9b3c6f0ed942e48dc89015e139 100644
--- a/pkg/analyzer/test/src/summary/summary_common.dart
+++ b/pkg/analyzer/test/src/summary/summary_common.dart
@@ -4749,6 +4749,19 @@ f() { // 1
     }
   }
 
+  test_executable_localVariables_catch_noVariables() {
+    String code = r'''
+f() {
+  try {
+    throw 42;
+  } on int {}
+}
+''';
+    UnlinkedExecutable executable = serializeExecutableText(code);
+    List<UnlinkedVariable> variables = executable.localVariables;
+    expect(variables, isEmpty);
+  }
+
   test_executable_localVariables_empty() {
     UnlinkedExecutable executable = serializeExecutableText(r'''
 f() {
@@ -4798,6 +4811,17 @@ f() { // 1
     }
   }
 
+  test_executable_localVariables_forLoop_noVariables() {
+    String code = r'''
+f() {
+  for (; true;) {}
+}
+''';
+    UnlinkedExecutable executable = serializeExecutableText(code);
+    List<UnlinkedVariable> variables = executable.localVariables;
+    expect(variables, isEmpty);
+  }
+
   test_executable_localVariables_inConstructor() {
     String code = r'''
 class C {