compiler,reflect: fix NumMethods for Interface type

[frenkel26]

Fixes #4260

[aykevl]

This change looks good to me.

Can you add a test? For example, you can add this one-line change:

--- a/testdata/reflect.go
+++ b/testdata/reflect.go
@@ -456,6 +456,7 @@ func showValue(rv reflect.Value, indent string) {
        case reflect.Interface:
                println(indent + "  interface")
                println(indent+"  nil:", rv.IsNil())
+               println(indent+"  NumMethod:", rv.NumMethod())
                if !rv.IsNil() {
                        showValue(rv.Elem(), indent+"  ")
                }

And then you can run the following:

go run ./testdata/reflect.go 2> testdata/reflect.txt

And then tinygo test should pass (it doesn't for me, but it probably will pass with your fix).

[dgryski]

LGTM. Thanks for the test.

[aykevl]

Looks good to me!
I confirmed it matches what go produces.

[dgryski]

I'm going to see if there are any more tests we can uncomment from reflect/all_test.go.

[dgryski]

#4276