Implement generic function type syntax in the VM (fixes #27966).

tests/language/language.status

Index: tests/language/language.status
diff --git a/tests/language/language.status b/tests/language/language.status
index 4c42b55c5b0f858a6ddfa8b277d5306909b2a58d..d7275cb069970a507e5927661d5b24ce7c2e8caa 100644
--- a/tests/language/language.status
+++ b/tests/language/language.status
@@ -53,11 +53,6 @@ redirecting_constructor_initializer_test: RuntimeError # Issue 23488
 
 async_star_regression_2238_test: CompileTimeError, RuntimeError # drt only runtime-errs.
 
-generic_function_typedef_test: Fail # Issue 27966
-generic_function_typedef2_test/none: Fail # Issue 27966
-generic_function_typedef2_test/04: Fail # Issue 27966
-generalized_function_type_test: Fail # Issue 27966
-
 [ ($compiler == none || $compiler == precompiler || $compiler == app_jit) && $checked ]
 # These generic functions tests pass for the wrong reason in checked mode,
 # because the parsed type parameters are mapped to dynamic type.
@@ -75,6 +70,7 @@ vm/debug_break_enabled_vm_test/01: Crash, OK # Expected to hit breakpoint.
 
 [ ($compiler == none || $compiler == precompiler || $compiler == app_jit) && $checked ]
 type_variable_bounds4_test/01: Fail # Issue 14006
+generalized_function_type_test: SkipSlow # Times out in checked mode. Generated test is too large.
 
 [ ($compiler == none || $compiler == precompiler || $compiler == app_jit) && (($runtime == vm || $runtime == dart_precompiled) || $runtime == drt || $runtime == dartium) ]
 dynamic_prefix_core_test/none: Fail # Issue 12478
@@ -160,6 +156,7 @@ vm/regress_24517_test: Pass, Fail # Issue 24517.
 
 [ $compiler == precompiler && $runtime == dart_precompiled ]
 vm/regress_27671_test: Skip # Unsupported
+generic_creation_test: Fail # regis investigating
 
 [ $runtime == dart_precompiled ]
 # Stacktraces in precompilation omit inlined frames.