Fix stack walking and reporting of default interface methods (dotnet/coreclr#21525)

Fix stack walking and reporting of default interface methods (dotnet/coreclr#21525)

Default interface methods in their unresolved state don't have a generic context. The generic context is only added once the method is resolved to its implementation.

Commit migrated from https://github.com/dotnet/coreclr/commit/352a5cb1b358ba7e3a5addbf7bd4a5fd73499683