Cleanup/optimize break_next_call: compile regex once

[disconnect3d]

The break_next_call function which steps through the execution has this functionality that it can stop on a target symbol checked via a regular expression.

However, both the regular expression as well as the string provided to it are constructed on each loop iteration (!). While Python regexes are cached internally, we should not rely on this functionality.

pwndbg/pwndbg/gdblib/next.py

Lines 107 to 113 in e37591b

	# return call if we match target address
	if ins.target_const and re.match(f"{symbol_regex}$", hex(ins.target)):
	return ins
	# return call if we match symbol name
	if ins.symbol and re.match(f"{symbol_regex}$", ins.symbol):
	return ins

Effectively, this issue is just about doing something like:

symbol_re = re.compile(f"{symbol_regex}$")

while ...:
    if ... and symbol_re.match(...): ...