In order to support tier 2 side-exits fromFOR_ITER variants, we need a target that has the same stack as the exhaustion guard.
Currently we can either jump to theEND_FOR, as we do for generators or the instruction afterwards, which we do forFOR_ITER.
In order to exit a guard we need a target in between those instructions, that pops the iterator, but not the value.
The compiler emits END_FOR; POP_TOP instead of END_FOR.
Previously:

   END_FOR (Pops two values) <- FOR_ITEN_GEN targets this   ...                       <- FOR_ITER targets this

Now:

   END_FOR (Pops one value)  <- FOR_ITEN_GEN targets this   POP_TOP (Pops one value)  <- _GUARD_NOT_EXHAUSTED can target this   ...                       <- FOR_ITER targets this

• Issue:Trace stitching #112354