revlog: explicitely pass the "indexfile" parameter

Authored by marmoute.


revlog: explicitely pass the "indexfile" parameter

Most of this was already done when introducing the target parameter, but some
remained. Having "indexfile" passed explicitely will help us to change the way
we address a revlog later in the stack. With the introduction of more generic
docket, the entry point will not necessarly be xxx.i file, and the actual
index files will have a variable name.

Differential Revision: https://phab.mercurial-scm.org/D10561