chuginate on macOS update to support universal binary #267

[nshaheed]

consider generating makefile that build for universal binary, or maybe can be an option, or something easily toggle-able in the makefile

duplicate of ccrma/chuck#267

[gewang]

as of 899c087 we have updated the default makefile.mac to build for the underlying native architecture, with added comments to easily switch between architecture target(s):

chugins/chuginate/template/makefile.mac

Lines 6 to 17 in 899c087

	# to build for the native architecture: (leave blank)
	# ARCHS?=
	#
	# to build for intel:
	# ARCHS?=x86_64
	#
	# to build for apple silicon:
	# ARCHS?=arm64
	#
	# to build a universal=binary chugin:
	# ARCHS?=x86_64 arm64
	ARCHS?=