Enforce function declaration format in bash8
Enforce function declaration format in bash8

Check that function calls look like ^function foo {$ in bash8, and fix
all existing failures of that check.  Add a note to HACKING.rst

Change-Id: Ic19eecb39e0b20273d1bcd551a42fe400d54e938
(cherry picked from commit aee18c749b0e3a1a3a6907a33db76ae83b8d41d9)

openstack-dev/bashate,locke105/bash8,openstack-dev/bashate