spesh logging the results of dispatch resolutions

gistfile1.txt

==========

Latest statistics for 'type-name' (cuid: 25, file: t/moar/53-dispatch.t:123)

Total hits: 9

Callsite 0x4d8910 (1 args, 1 pos)
Positional flags: 

    Callsite hits: 9

    Maximum stack depth: 11

    Type tuple 0
        Type 0: C1 (TypeObj)
        Hits: 4
        Maximum stack depth: 11
        Logged at offset:
            20:
                1 x type VMNull (TypeObj)
            16:
                2 x spesh plugin guard index 0

    Type tuple 1
        Type 0: C2 (TypeObj)
        Hits: 3
        Maximum stack depth: 11
        Logged at offset:
            20:
                1 x type VMNull (TypeObj)
            16:
                2 x spesh plugin guard index 1

    Type tuple 2
        Type 0: C3 (TypeObj)
        Hits: 2
        Maximum stack depth: 11
        Logged at offset:
            20:
                1 x type VMNull (TypeObj)
            16:
                1 x spesh plugin guard index 2

gistfile2.txt

{
    my class C1 { }
    my class C2 { }
    my class C3 { }
    my $count := 0;
    nqp::dispatch('boot-syscall', 'dispatcher-register', 'type-name', -> $capture {
        $count++;
        my $arg := nqp::dispatch('boot-syscall', 'dispatcher-track-arg', $capture, 0);
        my $arg-val := nqp::captureposarg($capture, 0);
        my str $name := $arg-val.HOW.name($arg-val);
        nqp::dispatch('boot-syscall', 'dispatcher-guard-type', $arg);
        nqp::dispatch('boot-syscall', 'dispatcher-delegate', 'boot-constant',
            nqp::dispatch('boot-syscall', 'dispatcher-insert-arg-literal-str',
                nqp::dispatch('boot-syscall', 'dispatcher-drop-arg', $capture, 0),
                0, $name));
    });
    sub type-name($obj) {
        nqp::dispatch('type-name', $obj)
    }

    ok(type-name(C1) eq 'C1', 'Dispatcher setting guard works');
    ok($count == 1, 'Dispatch callback ran once');
    ok(type-name(C1) eq 'C1', 'Can use it another time with the same type');
    ok($count == 1, 'Dispatch callback was not run again');

    ok(type-name(C2) eq 'C2', 'Can handle polymorphic sites when guard fails');
    ok($count == 2, 'Dispatch callback ran a second time for new type');
    ok(type-name(C2) eq 'C2', 'Second call with new type works');
    ok(type-name(C1) eq 'C1', 'Call with original type still works');
    ok($count == 2, 'Dispatch callback only ran a total of 2 times');

    ok(type-name(C3) eq 'C3', 'Can handle a third level of polymorphism');
    ok($count == 3, 'Dispatch callback ran a third time for new type');
    ok(type-name(C1) eq 'C1', 'Works with first type');
    ok(type-name(C2) eq 'C2', 'Works with second type');
    ok(type-name(C3) eq 'C3', 'Works with third type');
    ok($count == 3, 'There were no further dispatch callback invocations');
}