This is reducing nearby calls to TiGetClient() API when the value
can be looked up one time and stored in a local variable to make
other decisions about.
This is due to TiGetClient() potentially having a slightly higher
cost to call than previously, this is a kind of peephole
optimization approach (if I can see multiple getters used within
the window it got optmized).
'ticlient' was used for retrieval as ClientData so that future
greps across the codebase for `ti_client` should only match naked
access.
f942ae6e78