Go: support for aarch64 (#16083)

var/spack/repos/builtin/packages/go/package.py

@@ -6,6 +6,7 @@
 import os
 import llnl.util.tty as tty
 from spack import *
+import platform
 
 # - vanilla CentOS 7, and possibly other systems, fail a test:
 #   TestCloneNEWUSERAndRemapRootDisableSetgroups
@@ -87,7 +88,10 @@ class Go(Package):
     depends_on('git', type=('build', 'link', 'run'))
     # TODO: Make non-c self-hosting compilers feasible without backflips
     # should be a dep on external go compiler
-    depends_on('go-bootstrap', type='build')
+    if platform.machine() == 'aarch64':
+        depends_on('gcc languages=go', type='build')
+    else:
+        depends_on('go-bootstrap', type='build')
 
     # https://github.com/golang/go/issues/17545
     patch('time_test.patch', when='@1.6.4:1.7.4')