Profiling some code I'd written recently, I found that goto-char was
using 90% of CPU time in a large buffer with lots of properties and
overlays. Setting inhibit-point-motion-hooks helped, but it occurs to me
that the operation shouldn't have been expensive in the first place.
Nothing in the buffer had a point motion hook or an intangible property,
though, so the work goto-char was doing was pointless.

In addition to allowing callers to bind inhibit-point-motion-hooks, what
about tracking whether any property or overlay ever inserted into a
buffer uses one of these uncommon facilities? This way, the common case
is fast even without inhibit-point-motion-hooks.