pkg_resources.Distribution.hashcmp is slow

As it removes md5 fragment on the fly, pkg_resources.Distribution.hashcmp is slow:

@property
def hashcmp(self):
    return (
        self.parsed_version,
        self.precedence,
        self.key,
        _remove_md5_fragment(self.location),
        self.py_version or '',
        self.platform or '',
    )

Would there be side effects if location is changed into a property where the setter would not only store the location but also store the location without fragment ?

[gotcha]

The simple example below calls hashcmp (thus _remove_md5_fragment) nearly 1.3 million times:

import pkg_resources
import setuptools.package_index

pki = setuptools.package_index.PackageIndex()
req = pkg_resources.Requirement.parse('setuptools')
pki.obtain(req)

I guess that setuptools is the most patholigical case. Nevertheless, trying to obtain django calls hashcmp more than 200k times.

[gotcha]

It is always better to remove code when possible. Thanks for #2108

To answer your question above about real-world usage, I am in the process of removing zc.buildout dependency on setuptools.easy_install.

In a first phase, I plan to keep the dependency on setuptools.package_index. Is there some doc that presents how quick it will be deprecated ?