Fix valid_returns tests.

The valid return tests were misnamed and hence not run.  Also remove
duplicate tests from one file, and add status to the informal proposal.

Change-Id: I20179e81a0281302056f601ee3b7a51e2aec180e
Reviewed-on: https://dart-review.googlesource.com/73562
Commit-Queue: Leaf Petersen <leafp@google.com>
Reviewed-by: Kevin Millikin <kmillikin@google.com>

docs/language/informal/invalid_returns.md

@@ -2,6 +2,8 @@
 
 leafp@google.com
 
+Status: Ready for implementation
+
 **Note: Also see alternative presentation at the bottom for a dual presentation
 of these rules in terms of which things are errors, rather than which things are
 valid*.*

tests/language_2/invalid_returns/async_valid_returns_test.dart

@@ -20,7 +20,6 @@ FutureOr<Object> fovo = null;
 FutureOr<Null> fovn = null;
 FutureOr<int> fovi = null;
 
-
 /* Test the cases where expression bodied functions are more permissive
  * than block bodied functions (places where they behave the same
  * are tested below).
@@ -32,7 +31,6 @@ expression `e` has a valid return if:
   with return type `T` as defined below.
 */
 
-  
 void async_int_to_void_e() async => vi;
 Future<void> async_int_to_Future_void__e() async => vi;
 FutureOr<void> async_int_to_FutureOr_void__e() async => vi;
@@ -343,42 +341,34 @@ Future<int> async_Future_int__to_Future_int_() async {
   return fvi;
 }
 
-Future<void> async_int_to_Future_void__e() async => vi;
 Future<void> async_int_to_Future_void_() async {
   return vi;
 }
 
-Future<void> async_Object_to_Future_void__e() async => vo;
 Future<void> async_Object_to_Future_void_() async {
   return vo;
 }
 
-Future<void> async_FutureOr_int__to_Future_void__e() async => fovi;
 Future<void> async_FutureOr_int__to_Future_void_() async {
   return fovi;
 }
 
-Future<void> async_Future_int__to_Future_void__e() async => fvi;
 Future<void> async_Future_int__to_Future_void_() async {
   return fvi;
 }
 
-FutureOr<void> async_int_to_FutureOr_void__e() async => vi;
 FutureOr<void> async_int_to_FutureOr_void_() async {
   return vi;
 }
 
-FutureOr<void> async_Object_to_FutureOr_void__e() async => vo;
 FutureOr<void> async_Object_to_FutureOr_void_() async {
   return vo;
 }
 
-FutureOr<void> async_FutureOr_int__to_FutureOr_void__e() async => fovi;
 FutureOr<void> async_FutureOr_int__to_FutureOr_void_() async {
   return fovi;
 }
 
-FutureOr<void> async_Future_int__to_FutureOr_void__e() async => fvi;
 FutureOr<void> async_Future_int__to_FutureOr_void_() async {
   return fvi;
 }

tests/language_2/invalid_returns/sync_valid_returns_test.dart

@@ -37,7 +37,6 @@ void sync_FutureOr_int__to_void_e() => fovi;
 void sync_Future_Object__to_void_e() => fvo;
 void sync_FutureOr_Object__to_void_e() => fovo;
 
-
 /* Test the cases that apply only to block bodied  functions
  */
 
@@ -62,8 +61,6 @@ Null sync_empty_to_Null() {
 /* Test the cases that apply to both expression bodied and block bodied
  * functions
  */
-  
-
 
 /*
 * `return exp;` where `exp` has static type `S` is a valid return if:

tests/language_2/language_2_kernel.status

@@ -225,6 +225,7 @@ f_bounded_quantification_test/02: MissingCompileTimeError # Issue 33308
 factory4_test/00: MissingCompileTimeError # Issue 31590
 generic_methods_bounds_test/01: MissingCompileTimeError # Issue 33308
 generic_methods_recursive_bound_test/02: MissingCompileTimeError # Issue 33308
+invalid_returns/async_valid_returns_test: CompileTimeError #34014
 issue31596_super_test/02: MissingCompileTimeError # Issue 31596
 issue31596_super_test/04: MissingCompileTimeError # Issue 31596
 malbounded_instantiation_test/01: MissingCompileTimeError # Issue 33308