Add helper function to dis.Instruction and use it to reduce churn in test_dis

Author: markshannon

Lib/dis.py

@@ -310,7 +310,6 @@ def show_code(co, *, file=None):
 )
 
 _Instruction.opname.__doc__ = "Human readable name for operation"
-_Instruction.opcode.__doc__ = "Numeric code for operation"
 _Instruction.arg.__doc__ = "Numeric argument to operation (if any), otherwise None"
 _Instruction.argval.__doc__ = "Resolved arg value (if known), otherwise same as arg"
 _Instruction.argrepr.__doc__ = "Human readable description of operation argument"
@@ -376,6 +375,10 @@ class Instruction(_Instruction):
                         entries (if any)
     """
 
+    @staticmethod
+    def make(opname, arg, argval, argrepr, offset, start_offset, starts_line, line_number, label=None, positions=None, cache_info=None):
+        return Instruction(opname, _all_opmap[opname], arg, argval, argrepr, offset, start_offset, starts_line, line_number, label, positions, cache_info)
+
     @property
     def oparg(self):
         """Alias for Instruction.arg."""