The basic premise of optimizing traces is that most branches are highly biased.
So we use DEOPT_IF to branch in the uncommon case.
However in the optimizer we may want to move work to exit branches, which needs jumps.
Unifying branches and jumps also simplifies the tier 2 interpreter and the JIT compiler.

So, let's merge jumps and branches, as follows:

• Convert most, if not all jumps in the tier 2 code to DEOPT_IFs in bytecodes.c
• Convert deopts into jumps internally to allow work like SET_IP to be sunk into exit branches.

See also #111610

Linked PRs

• GH-111848: Tidy up tier 2 handling of FOR_ITER specialization by using DEOPT_IF instead of jumps. #111849
• GH-111848: Convert remaining jumps to deopts into tier 2 code. #112045
• GH-111848: Set the IP when de-optimizing #112065
• gh-111848: Clean up RESERVE() macro #112274