Does the platform provide and supports the Boehm's GC library?

Property definitions

	# Does the platform provide and supports the Boehm's GC library?
	fun supports_libgc: Bool do return true

src/platform/platform.nit:116,2--117,40

	redef fun supports_libgc do return true

src/platform/android.nit:39,2--40

	redef fun supports_libgc do return false

src/platform/emscripten.nit:36,2--41

	redef fun supports_libgc do return true

src/platform/ios.nit:35,2--40