txscript: Make op callbacks take opcode and data.

This converts the callback function defined on the internal opcode
struct to accept the opcode and data slice instead of a parsed opcode as
the final step towards removing the parsed opcode struct and associated
supporting code altogether.

It also updates all of the callbacks and tests accordingly and finally
removes the now unused parsedOpcode struct.

The final results for the raw script analysis and tokenizer
optimizations are as follows:

benchmark                                       old ns/op     new ns/op     delta
BenchmarkIsPayToScriptHash-8                    62393         0.51          -100.00%
BenchmarkIsPubKeyHashScript-8                   62228         0.56          -100.00%
BenchmarkGetSigOpCount-8                        61051         658           -98.92%
BenchmarkExtractPkScriptAddrsLarge-8            60713         17.2          -99.97%
BenchmarkExtractPkScriptAddrs-8                 289           17.9          -93.81%
BenchmarkIsWitnessPubKeyHash-8                  61688         0.42          -100.00%
BenchmarkIsUnspendable-8                        656           520           -20.73%
BenchmarkExtractAtomicSwapDataPushesLarge-8     61332         44.0          -99.93%
BenchmarkExtractAtomicSwapDataPushes-8          990           260           -73.74%
BenchmarkDisasmString-8                         102902        39754         -61.37%
BenchmarkGetPreciseSigOpCount-8                 130223        715           -99.45%
BenchmarkScriptParsing-8                        63464         681           -98.93%
BenchmarkIsMultisigScriptLarge-8                64166         5.83          -99.99%
BenchmarkIsMultisigScript-8                     630           58.5          -90.71%
BenchmarkPushedData-8                           64837         1779          -97.26%
BenchmarkCalcSigHash-8                          3627895       3605459       -0.62%
BenchmarkIsPubKeyScript-8                       62323         2.83          -100.00%
BenchmarkIsPushOnlyScript-8                     62412         569           -99.09%
BenchmarkIsWitnessScriptHash-8                  61243         0.56          -100.00%
BenchmarkGetScriptClass-8                       61515         16.4          -99.97%
BenchmarkIsNullDataScript-8                     62495         2.53          -100.00%
BenchmarkIsMultisigSigScriptLarge-8             69328         2.52          -100.00%
BenchmarkIsMultisigSigScript-8                  2375          141           -94.06%
BenchmarkGetWitnessSigOpCountP2WKH-8            504           72.0          -85.71%
BenchmarkGetWitnessSigOpCountNested-8           1158          136           -88.26%
BenchmarkIsWitnessPubKeyHash-8                  68927         0.53          -100.00%
BenchmarkIsWitnessScriptHash-8                  62774         0.63          -100.00%

benchmark                                       old allocs     new allocs     delta
BenchmarkIsPayToScriptHash-8                    1              0              -100.00%
BenchmarkIsPubKeyHashScript-8                   1              0              -100.00%
BenchmarkGetSigOpCount-8                        1              0              -100.00%
BenchmarkExtractPkScriptAddrsLarge-8            1              0              -100.00%
BenchmarkExtractPkScriptAddrs-8                 1              0              -100.00%
BenchmarkIsWitnessPubKeyHash-8                  1              0              -100.00%
BenchmarkIsUnspendable-8                        1              0              -100.00%
BenchmarkExtractAtomicSwapDataPushesLarge-8     1              0              -100.00%
BenchmarkExtractAtomicSwapDataPushes-8          2              1              -50.00%
BenchmarkDisasmString-8                         46             51             +10.87%
BenchmarkGetPreciseSigOpCount-8                 3              0              -100.00%
BenchmarkScriptParsing-8                        1              0              -100.00%
BenchmarkIsMultisigScriptLarge-8                1              0              -100.00%
BenchmarkIsMultisigScript-8                     1              0              -100.00%
BenchmarkPushedData-8                           7              6              -14.29%
BenchmarkCalcSigHash-8                          1335           712            -46.67%
BenchmarkIsPubKeyScript-8                       1              0              -100.00%
BenchmarkIsPushOnlyScript-8                     1              0              -100.00%
BenchmarkIsWitnessScriptHash-8                  1              0              -100.00%
BenchmarkGetScriptClass-8                       1              0              -100.00%
BenchmarkIsNullDataScript-8                     1              0              -100.00%
BenchmarkIsMultisigSigScriptLarge-8             5              0              -100.00%
BenchmarkIsMultisigSigScript-8                  3              0              -100.00%
BenchmarkGetWitnessSigOpCountP2WKH-8            2              0              -100.00%
BenchmarkGetWitnessSigOpCountNested-8           4              0              -100.00%
BenchmarkIsWitnessPubKeyHash-8                  1              0              -100.00%
BenchmarkIsWitnessScriptHash-8                  1              0              -100.00%

benchmark                                       old bytes     new bytes     delta
BenchmarkIsPayToScriptHash-8                    311299        0             -100.00%
BenchmarkIsPubKeyHashScript-8                   311299        0             -100.00%
BenchmarkGetSigOpCount-8                        311299        0             -100.00%
BenchmarkExtractPkScriptAddrsLarge-8            311299        0             -100.00%
BenchmarkExtractPkScriptAddrs-8                 768           0             -100.00%
BenchmarkIsWitnessPubKeyHash-8                  311299        0             -100.00%
BenchmarkIsUnspendable-8                        1             0             -100.00%
BenchmarkExtractAtomicSwapDataPushesLarge-8     311299        0             -100.00%
BenchmarkExtractAtomicSwapDataPushes-8          3168          96            -96.97%
BenchmarkDisasmString-8                         389324        130552        -66.47%
BenchmarkGetPreciseSigOpCount-8                 623367        0             -100.00%
BenchmarkScriptParsing-8                        311299        0             -100.00%
BenchmarkIsMultisigScriptLarge-8                311299        0             -100.00%
BenchmarkIsMultisigScript-8                     2304          0             -100.00%
BenchmarkPushedData-8                           312816        1520          -99.51%
BenchmarkCalcSigHash-8                          1373812       1290507       -6.06%
BenchmarkIsPubKeyScript-8                       311299        0             -100.00%
BenchmarkIsPushOnlyScript-8                     311299        0             -100.00%
BenchmarkIsWitnessScriptHash-8                  311299        0             -100.00%
BenchmarkGetScriptClass-8                       311299        0             -100.00%
BenchmarkIsNullDataScript-8                     311299        0             -100.00%
BenchmarkIsMultisigSigScriptLarge-8             330035        0             -100.00%
BenchmarkIsMultisigSigScript-8                  9472          0             -100.00%
BenchmarkGetWitnessSigOpCountP2WKH-8            1408          0             -100.00%
BenchmarkGetWitnessSigOpCountNested-8           3200          0             -100.00%
BenchmarkIsWitnessPubKeyHash-8                  311299        0             -100.00%
BenchmarkIsWitnessScriptHash-8                  311299        0             -100.00%

txscript/engine.go

@@ -385,8 +385,7 @@ func (vm *Engine) executeOpcode(op *opcode, data []byte) error {
 		}
 	}
 
-	pop := parsedOpcode{opcode: op, data: data}
-	return op.opfunc(&pop, vm)
+	return op.opfunc(op, data, vm)
 }
 
 // checkValidPC returns an error if the current script position is not valid for