This CL removes unused utils.InstallFunctions, utils.InstallGetter(),
utils.SetFunctionName, utils.OverrideFunction and respective runtime
functions (%FunctionSetSharedName and %FunctionRemovePrototype).

This CL is one of a series of cleanup CL which are the preliminary steps for
improving function closures creation.

Bug: v8:6459
Change-Id: I0fb5940ed628f0c1958f585411e2fca3e2038054
Reviewed-on: https://chromium-review.googlesource.com/548037
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46336}