Using a table of function pointers is faster than using a switch
followed by a function call. Also more aggressively inline binding
methods.

Based on contribution by mtavenrath@nvidia.com.

In total this patch sequence improves the performance of a buffer
binding perf test by up to 27%.

Test: BindingsBenchmark.Run/gl_100_objects_allocated_at_initialization
Bug: angleproject:2891
Change-Id: Iaab1e2a135b635bd72736d7d1d4271562c3a4ece
Reviewed-on: https://chromium-review.googlesource.com/c/1281783
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Frank Henigman <fjhenigman@chromium.org>