Replace num-bigint with malachite-bigint

[qingshi163]

No description provided.

[youknowone]

BigUint::parse_bytes seems rejecting _ in input, which is legal on num-bigint.

[qingshi163]

Don't change bytes_to_int, malachite-bigint should handle it. I think it is a bug involved on the last commit

[youknowone]

@qingshi163 Can we run a benchmark about this? A benchmark with many small int binary operations will fit.

[corona10]

@youknowone @qingshi163
FYI for the Fibonacci benchmark

Mean +- std dev: [base] 60.0 us +- 2.0 us -> [pr_4952] 55.4 us +- 1.1 us: 1.08x faster

import pyperf

runner = pyperf.Runner()
runner.timeit(name="bench fib",
              stmt="""
_ = fib(10)
""",
              setup = """
def fib(n):
    if n == 0:
        return 0
    if n == 1 or n == 2:
        return 1
    return fib(n-1) + fib(n-2)
""")

[youknowone]

@corona10 Thank you!

[youknowone]

hmm, this is unexpected. what's changed?

[youknowone]

I can't locally reproduce it.

[youknowone]

ah, main is already broken