Merge branch 'bc/reread-attributes-during-rebase'

The "git am" based backend of "git rebase" ignored the result of
updating ".gitattributes" done in one step when replaying
subsequent steps.

* bc/reread-attributes-during-rebase:
am: reload .gitattributes after patching it
path: add a function to check for path suffix

diff --cc apply.c
Simple merge

diff --cc t/t3400-rebase.sh
Simple merge