Revert "Deprecate the use of `Function` as a class."

pkg/analyzer/test/generated/hint_code_test.dart

Index: pkg/analyzer/test/generated/hint_code_test.dart
diff --git a/pkg/analyzer/test/generated/hint_code_test.dart b/pkg/analyzer/test/generated/hint_code_test.dart
index 013ffe281867cbdeca13e8d22ea0a64e127811ab..52b0febf25bf92c570fbce05e5e66a5dc5004015 100644
--- a/pkg/analyzer/test/generated/hint_code_test.dart
+++ b/pkg/analyzer/test/generated/hint_code_test.dart
@@ -944,65 +944,6 @@ class B extends A {
     verify([source]);
   }
 
-  test_deprecatedFunction_class() async {
-    Source source = addSource(r'''
-class Function {}
-''');
-    await computeAnalysisResult(source);
-    assertErrors(source, [HintCode.DEPRECATED_FUNCTION_CLASS_DECLARATION]);
-    verify([source]);
-  }
-
-  test_deprecatedFunction_extends() async {
-    Source source = addSource(r'''
-class A extends Function {}
-''');
-    await computeAnalysisResult(source);
-    assertErrors(source, [
-      HintCode.DEPRECATED_EXTENDS_FUNCTION,
-      StaticWarningCode.FUNCTION_WITHOUT_CALL
-    ]);
-    verify([source]);
-  }
-
-  test_deprecatedFunction_extends2() async {
-    Source source = addSource(r'''
-class Function {}
-class A extends Function {}
-''');
-    await computeAnalysisResult(source);
-    assertErrors(source, [
-      HintCode.DEPRECATED_FUNCTION_CLASS_DECLARATION,
-      HintCode.DEPRECATED_EXTENDS_FUNCTION
-    ]);
-    verify([source]);
-  }
-
-  test_deprecatedFunction_mixin() async {
-    Source source = addSource(r'''
-class A extends Object with Function {}
-''');
-    await computeAnalysisResult(source);
-    assertErrors(source, [
-      HintCode.DEPRECATED_MIXIN_FUNCTION,
-      StaticWarningCode.FUNCTION_WITHOUT_CALL
-    ]);
-    verify([source]);
-  }
-
-  test_deprecatedFunction_mixin2() async {
-    Source source = addSource(r'''
-class Function {}
-class A extends Object with Function {}
-''');
-    await computeAnalysisResult(source);
-    assertErrors(source, [
-      HintCode.DEPRECATED_FUNCTION_CLASS_DECLARATION,
-      HintCode.DEPRECATED_MIXIN_FUNCTION
-    ]);
-    verify([source]);
-  }
-
   test_divisionOptimization_double() async {
     Source source = addSource(r'''
 f(double x, double y) {