ZJIT: Fix internal compiler error looking up profiles for trace_getinstancevariable (#14969)

We treat getinstancevariable differently from other opcodes: it does not
look at the stack for its self operand, but instead looks at
`cfp->self`. In some cases, we might see the `trace_` variant in the
front-end, so make sure we treat that the same.

Example repro:

```
def test
  @foo
end

28.times do
  test
end

trace = TracePoint.trace(:call) do |tp|
  puts tp.method_id
end

trace.enable do
  30.times do
    test
  end
end
```

0 files changed, 0 insertions, 0 deletions