[PATCH 0/5] streaming.c: refactor for smaller + easier to understand code

This is a prep series for my yet-to-be-sent re-roll of [1],
aka. ab/fsck-unexpected-type.

Jeff King had a comment in [2] saying it was odd to have an "oi2"
variable, that was because there was on an "oi" name already defined
via the new-gone open_method_decl(loose) macro. As we'll see we could
do without the initial "oi" and a few other types of indirection in
this interface.

Junio: Could you eject ab/fsck-unexpected-type while this is being
considered/cooked? I didn't really see how to address Jeff's feedback
about that variable name in a way that wouldn't just make something
like this refactoring part of an even bigger series. I think ejecting
the functional changes & trying to get this in first is the least
worst approach at this point. Eventually I'll submit a re-roll of
ab/fsck-unexpected-type either based on this, or master (if it's
landed already).

1. https://lore.kernel.org/git/cover-0.6-00000000000-20210413T093734Z-avarab@gmail.com/#t (local)
2. https://lore.kernel.org/git/YILZHiuUyj0mt958@coredump.intra.peff.net/ (local)

Ævar Arnfjörð Bjarmason (5):
  streaming.c: avoid forward declarations
  streaming.c: remove enum/function/vtbl indirection
  streaming.c: remove {open,close,read}_method_decl() macros
  streaming.c: stop passing around "object_info *" to open()
  streaming.c: move {open,close,read} from vtable to "struct
    git_istream"

 streaming.c | 268 ++++++++++++++++++++++------------------------------
 1 file changed, 115 insertions(+), 153 deletions(-)

-- 
2.31.1.838.g7ac6e98bb53