Use `GOTO_ERROR(error)` instead of `goto error`.
This macro is defined differently in the tier two interpreter.

This replaces PYTHONUOPSDEBUG=N. The meaning of N is the same (for now):

  0: no tracing
  1: print when tier 2 trace created
  2: print contents of tier 2 trace
  3: print every uop executed
  4: print optimization attempts and details
  5: print tier 1 instructions and stack

- Remove CHECK_EVAL_BREAKER() from top of Tier 2 loop
- Make Tier 2 default case Py_UNREACHABLE() in non-debug mode
- GOTO_TIER_TWO() macro instead of `goto enter_tier_two`
- Inline ip_offset (Tier 2 LOAD_IP() is now a no-op)
- Move #define/#under TIER_ONE/TIER_TWO into generated .c.h files
- ceval_macros.h defines Tier 1 macros, Tier 2 is inlined in ceval.c

(I accidentally kept this commit after pushing it experimentally.
This means I've been testing with uops on all the time, which is
actually pretty amazing.)

This reverts commit e0e60ce.

Using `GOTO_TIER_ONE()` macro. This should make things simpler
for Justin.