Re: Remove diff machinery dependency from read-cache

Nicolas Pitre [off-list ref] writes:

I do use it, but for developing/debugging pack stuff.  I don't suggest
removing it, but I don't think making it a built-in has value either.

I thought people _might_ have used it for satistics purposes, but it
appears that the command doesn't even give in-pack size of objects nor
delta chain length, so probably anybody doing pack statistics would be
using "verify-pack -v" and wouldn't mind if it became test-show-index.

So I really think that Linus' patch (which is missing hex.c btw) is a 
good thing to do, even if only for the cleanup value.

Then, git-show-index could probably become test-show-index and no longer 
leave the build directory.

Yeah, I think that is a sensible long term plan, too.