Use the gold linker for aarch64/linux (#9673)

Authored by erikd.

Description

Use the gold linker for aarch64/linux (Trac #9673)

Like 32 bit Arm, Aarch64 requires use of the gold linker.

Signed-off-by: Erik de Castro Lopo <erikd@mega-nerd.com>

Test Plan: 'make install' on aarch64, validate elsewhere

Reviewers: rwbarton, bgamari, austin

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D858

GHC Trac Issues: Trac #9673