When the ToString Torque builtin has already found and called a
`toString` or `valueOf` method on a JSReceiver, and still needs
to call the runtime afterwards, it should do so with the result
of that first step, as opposed to the original input.

Fixed: v8:11689
Change-Id: I672249f9a6c230c3e61921b043f372c25a0178cf
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3097270Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76326}