Translate custom name sections during instrumentation

> If this is a name section (`custom.name() == "name"`), don't we need to shift function indices down for the hostcall strategy?

_Originally posted by @cfallin in https://github.com/fitzgen/winliner/pull/2#discussion_r1333600132_

Start by locating the instrumentation path that checks custom.name() == "name" and read how the hostcall strategy shifts function indices. Verify how the name section should be translated alongside those shifts; done means custom name entries remain aligned with the instrumented function indices. No file or test is named in the issue.

Written by the indexing model from the issue text.