[netcore] Test fixes.
* EqualityComparer.cs: Add LastIndexOf ().
* RuntimeAssembly.cs: Implement CreateAssemblyName ().
* AssemblyLoadContext.cs: Handle windows paths. Add DoAssemblyResolve () method.
* Array.cs: Add/fix error handling. Implement LastIndexOf ()/GetRawArrayData ().
* Attribute.cs: Implement.
* Buffer.cs: Add/fix error handling.
* DefaultBinder.cs: Implement.
* RuntimeType.cs: Implement HasSameMetadataDefinitionAs ().
* RuntimeEventInfo.cs: Ditto.
* RuntimeFieldInfo.cs: Ditto.
* RuntimeMethodInfo.cs: Ditto.
* RuntimePropertyInfo.cs: Ditto.
* MonoCustomAttrs.cs: Add eror handling. Implement inheritance support for parameters.
* gc.cs: Fix error handling.
* rttype.cs: Fix handling of null namespaces.
17 files changed: