[netcore] add some intrinsics for interpreter (#14547)

[netcore] add some intrinsics for interpreter (#14547)

[netcore] add some intrinsics for interpreter

```console
$ MONO_ENV_OPTIONS='--interp' make -C netcore xtest-System.Runtime.Tests
Microsoft.DotNet.XUnitConsoleRunner v2.5.0 (64-bit .NET Core 3.0.0-preview5-27620-01)
  Discovering: System.Runtime.Tests (method display = ClassAndMethod, method display options = None)
  Discovered:  System.Runtime.Tests (found 5266 of 5402 test cases)
  Starting:    System.Runtime.Tests (parallel test collections = on, max threads = 16)
[...]
  Finished:    System.Runtime.Tests
=== TEST EXECUTION SUMMARY ===
   System.Runtime.Tests  Total: 32485, Errors: 0, Failed: 23, Skipped: 2, Time: 126.432s
```
See failures here: https://gist.github.com/lewurm/c8372b0c7ba6a78cf8b7b7b8c7090820