Use regex lookaround in asm sanitize

[disinvite]

The regular expressions used in asm sanitize looked like this:

ptr_replace_regex = re.compile(r"\[(0x[0-9a-f]+)\]")

i.e. capturing the surrounding square brackets as part of the total match.

re.sub will replace the entire match with a string or the return value of a function. We use the function, but match.group(0) included more than just the hex value, so we used a hacky string replacement to get it working. The correct way is to use lookaround expressions to match with the surrounding characters but to not include them in group(0).

I also removed an edge case that makes no sense. The expression that detects immediate value operands would allow a replacement of the first operand, which is the destination in intel syntax. But an immediate value can never be the destination. I think this was there to cover replacement for single operand instructions, but we already match the ones we want earlier in the function: call, push, and jumps.

[jonschz]

looks good!