[mono][tests] Fix FullAOT runtime generic methods test (#77079)

* get vtable method slot by using its declaring

Author: kotlarmilos

src/mono/mono/mini/mini-generic-sharing.c

@@ -2279,7 +2279,12 @@ instantiate_info (MonoMemoryManager *mem_manager, MonoRuntimeGenericContextInfoT
 		} else {
 			ioffset = 0;
 		}
-		slot = mono_method_get_vtable_slot (info->method);
+		
+		if (info->method->is_generic == 0 && mono_class_is_ginst (info->method->klass)) {
+			slot = mono_method_get_vtable_slot (((MonoMethodInflated*)(info->method))->declaring);
+		} else {
+			slot = mono_method_get_vtable_slot (info->method);
+		}
 		g_assert (slot != -1);
 		g_assert (m_class_get_vtable (info->klass));
 		method = m_class_get_vtable (info->klass) [ioffset + slot];
@@ -2329,7 +2334,11 @@ instantiate_info (MonoMemoryManager *mem_manager, MonoRuntimeGenericContextInfoT
 		} else {
 			ioffset = 0;
 		}
-		slot = mono_method_get_vtable_slot (info->method);
+		if (info->method->is_generic == 0 && mono_class_is_ginst (info->method->klass)) {
+			slot = mono_method_get_vtable_slot (((MonoMethodInflated*)(info->method))->declaring);
+		} else {
+			slot = mono_method_get_vtable_slot (info->method);
+		}
 		g_assert (slot != -1);
 		g_assert (m_class_get_vtable (info->klass));
 		method = m_class_get_vtable (info->klass) [ioffset + slot];

src/tests/issues.targets

@@ -3068,10 +3068,6 @@
             <Issue>https://github.com/dotnet/runtime/issues/57352</Issue>
         </ExcludeList>
 
-        <ExcludeList Include = "$(XunitTestBinBase)/Loader/classloader/DefaultInterfaceMethods/constrainedcall/constrained2_gm/**">
-            <Issue>https://github.com/dotnet/runtime/issues/57512</Issue>
-        </ExcludeList>
-
         <ExcludeList Include="$(XunitTestBinBase)/Interop/DisabledRuntimeMarshalling/DisabledRuntimeMarshalling_Disabled_NativeAssemblyEnabled/**">
             <Issue>This test includes an intentionally-invalid UnmanagedCallersOnly method. Invalid UnmanagedCallersOnly methods cause failures at AOT-time.</Issue>
         </ExcludeList>