[BUG] OP_CODESEPARATOR handling

[sander2]

When running the command below, you can observe that the code separate position does not get correctly set by OP_CODESEPARATOR - it just always gets set to 0. I believe this is because opcode_pos does not correctly get incremented.

Run this:

btcdeb --txin=020000000001010b6ad48b306c6cc97e2850b4f84f35f4373a2bdf8abf17f46aa47947ba7827620000000000fdffffff0273ed052a010000002251205c25084d7b295ec36f1b81f4f7ceb0671a2d15429a8cf101ad454644208a53e7e803000000000000225120c61c497e749d1d077c04eabf8cb78764ced26358589251012e01a65bab8deae5024730440220602e8f9f2a86d648c2aa6e4683a55d14a0b7fed7bccacaf1e16d073d89977a9b022025e26e4e05309621cd8fe50ca6f11d0f1a85c9f33d24eb76c1615d024ddc585d01210368b179525abdc1f2256dce937648896a2d0ff3ab5aa6dde4a45c3da852d39b7cd4000000 --tx=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 --debug=sighash

Then repeat step instruction multiple times. You'll see the

 << code separator position
#004 00000000

Note: this is for a taproot script, which I believe has different OP_CODESEPARATOR rules than a normal segwit script.