Re: [PATCH 01/27] *: remove 'const' qualifier for struct index_state

"Derrick Stolee via GitGitGadget" [off-list ref] writes:

From: Derrick Stolee <redacted>

Several methods specify that they take a 'struct index_state' pointer
with the 'const' qualifier because they intend to only query the data,
not change it. However, we will be introducing a step very low in the
method stack that might modify a sparse-index to become a full index in
the case that our queries venture inside a sparse-directory entry.

This change only removes the 'const' qualifiers that are necessary for
the following change which will actually modify the implementation of
index_name_stage_pos().

This step has a bit of interaction with Matheus's "git add/rm" work
in sparse checkout (mt/add-rm-in-sparse-checkout), which I believe
is still in a bit of flux.  I didn't check potential conflicts the
remainder of the series may have with other in-flight topics.

So, I may throw review comments at the patches in this topic as if
they are standalone, but please do not be upset if it didn't appear
in the 'seen' topic.

Thanks.