GH-103082: Implementation of PEP 669: Low Impact Monitoring for CPython (GH-103083)

* The majority of the monitoring code is in instrumentation.c

* The new instrumentation bytecodes are in bytecodes.c

* legacy_tracing.c adapts the new API to the old sys.setrace and sys.setprofile APIs

Python/makeopcodetargets.py

@@ -32,7 +32,6 @@ def write_contents(f):
     """
     opcode = find_module('opcode')
     targets = ['_unknown_opcode'] * 256
-    targets[255] = "TARGET_DO_TRACING"
     for opname, op in opcode.opmap.items():
         if not opcode.is_pseudo(op):
             targets[op] = "TARGET_%s" % opname