reflect: update Select to panic early on excessive input cases
The runtime implementation of select has an upper limit on the number of
select cases that are supported in order to maintain low stack memory
usage. Rather than support an arbitrary number of select cases, we've
opted to panic early with a useful message pointing the user directly
at the problem.
Fixes #37350
Change-Id: Id129ba281ae120387e681ef96be8adcf89725840
Reviewed-on: https://go-review.googlesource.com/c/go/+/220583
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>