build: silvercity: mac: add special ARCHFLAGS to avoid building i386

(integrated from komodo (trunk) change 78724 by toddw)

git-svn-id: http://svn.openkomodo.com/repos/openkomodo/trunk/src/silvercity@12485 b87d16e7-d29f-4ee1-b5ec-817d645d335f
build: silvercity: mac: add special ARCHFLAGS to avoid building i386 (try 2)

(integrated from komodo (trunk) change 78730 by toddw)

git-svn-id: http://svn.openkomodo.com/repos/openkomodo/trunk/src/silvercity@12489 b87d16e7-d29f-4ee1-b5ec-817d645d335f
build: silvercity: mac: clang does not support gcc options - so remove them

(integrated from komodo (trunk) change 79272 by toddw)

git-svn-id: http://svn.openkomodo.com/repos/openkomodo/trunk/src/silvercity@12648 b87d16e7-d29f-4ee1-b5ec-817d645d335f