Fixes [Bug #21256]

Co-Authored-By: Earlopain <14981592+Earlopain@users.noreply.github.com>

Since cb419e3912f0514b8151469b0a4a4b83cbbcce78 we're no longer testing
this case because foo is redefined on obj1.

This reverts commit 265059603c3aa6a13f90096c71b32046a17938f3.

It was failing to set the leads, like numblocks do, causing the result to be wrapped in an array

Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>

The following is crashing for me:

```shell
ruby --yjit --yjit-call-threshold=1 -e '1.tap { raise rescue p it }'

ruby: YJIT has panicked. More info to follow...
thread '<unnamed>' panicked at ./yjit/src/codegen.rs:2402:14:
...
```

It seems `it` sometimes points to the wrong value:

```shell
ruby -e '1.tap { raise rescue p it }'
false

ruby -e '1.tap { begin; raise; ensure; p it; end } rescue nil'
false
```

But only when `$!` is set:

```shell
ruby -e '1.tap { begin; nil; ensure; p it; end }'
1

ruby -e '1.tap { begin; nil; rescue; ensure; p it; end }'
1

ruby -e '1.tap { begin; raise; rescue; ensure; p it; end }'
1
```

Fixes [Bug #21031]