Makefile recursion issue with SDL2

[Bill-Gray]

Attempts to run make with SDL2 get me this message :

Makefile:60: *** Recursive variable 'CC' references itself (eventually).  Stop.

And sure enough, lines 20 and 60 read, respectively,

PREFIX = $(shell $(CC) -dumpmachine)
CC		= $(PREFIX)-gcc

Haven't puzzled it out yet. For the nonce, running make CC=cc works around the problem.

[Bill-Gray]

As noted on #302, this is now fixed (see commit ac96c55).