Update config.guess to modern version which recognizes x86_64 architecture for Darwin (MacOS)

Update osversion script to recognize x86_64 triples for Darwin as Darwin
Update machinetype script to return 386 for MacOS El Capitan (10.11), x86_64 for other versions
Add makefile-darwin.x86_64-x for compiling in 64-bit mode on later MacOS versions

	modified:   config.guess
	modified:   machinetype
	new file:   makefile-darwin.x86_64-x
	modified:   osversion

bin/machinetype

@@ -16,6 +16,7 @@ case "$os" in
         sparc-*)	      echo sparc ;;
         alpha-*)	      echo alpha ;;
 	i*86-*-*)             echo 386 ;;
+        x86_64-apple-darwin15*) echo 386 ;;
 	x86_64-*)	      echo x86_64 ;;
         powerpc-*)	      echo ppc ;;
 esac

bin/makefile-darwin.x86_64-x

@@ -0,0 +1,53 @@
+# Options for MacOS, x86 processor, X windows
+
+CC = clang -m64 -std=gnu89 -funsigned-char
+OEXT=.o
+
+XFILES = $(OBJECTDIR)xmkicon.o \
+	$(OBJECTDIR)xbbt.o \
+	$(OBJECTDIR)dspif.o \
+	$(OBJECTDIR)xinit.o \
+	$(OBJECTDIR)xscroll.o \
+	$(OBJECTDIR)xcursor.o \
+	$(OBJECTDIR)xlspwin.o \
+	$(OBJECTDIR)xrdopt.o \
+	$(OBJECTDIR)xwinman.o
+
+
+XVERSION = XV11R4
+XFLAGS = -I/opt/X11/include -DXWINDOW -DNOPIXRECT -D$(XVERSION) # $(CLXFLAGS)
+
+# OPTFLAGS is normally -O2.
+OPTFLAGS =  -O1 -g
+DISPOPTFLAGS = -O1 -g
+FPFLAGS =
+DEBUGFLAGS = # -DDEBUG -DOPTRACE
+DFLAGS = $(DEBUGFLAGS) -DFSERROR -DNEW_STORAGE -DMACOSX -DOLD_CURSOR -DUSETERMIOS \
+	-DBYTESWAP -DFORKCOMM -DNOFORN -DLOGINT  $(XFLAGS) \
+	-DRELEASE=351
+
+LDFLAGS = -L/usr/X11/lib -lX11 -lm
+LDELDFLAGS =  -L/usr/X11/lib -lX11 -lm
+
+INLINE = # $(SRCDIR)dspSPARC.il
+BITBLTFILE = # $(OBJECTDIR)bbtSPARC.o
+BYTESWAPFILES = $(OBJECTDIR)byteswap.o
+
+OBJECTDIR = ../$(RELEASENAME)/
+
+default	: ../$(OSARCHNAME)/lde ../$(OSARCHNAME)/ldex
+
+############
+#
+#      Normal compilation for xc.o without optimized dispatch loop hacks
+#
+############
+$(OBJECTDIR)xc.o:      $(SRCDIR)xc.c $(INCDIR)lispemul.h  $(INCDIR)emlglob.h \
+	$(INCDIR)address.h \
+	$(INCDIR)adr68k.h  $(INCDIR)stack.h  $(INCDIR)lspglob.h \
+	$(INCDIR)lsptypes.h  $(INCDIR)lispmap.h  $(INCDIR)cell.h \
+	$(INCDIR)initatms.h  $(INCDIR)gc.h  \
+	$(INCDIR)arith.h $(INCDIR)stream.h \
+	$(INCDIR)tos1defs.h  $(INCDIR)tosret.h \
+	$(INCDIR)tosfns.h  $(INCDIR)inlineC.h $(INCDIR)car-cdr.h $(INCDIR)conspage.h $(INCDIR)llstk.h
+	$(CC) $(DISPRFLAGS) -UOPDISP  $(SRCDIR)xc.c -I$(INCDIR) -o $(OBJECTDIR)xc.o

bin/osversion

@@ -11,7 +11,7 @@ case "$os" in
         sparc-sun-solaris2*)	echo sunos5 ;;
         alpha-dec-osf1)	      echo osf1 ;;
 	i386-*-solaris*)      echo sunos5 ;;
-	i386-apple-darwin*)	echo darwin ;;
+	*-apple-darwin*)	echo darwin ;;
         *-*-linux*)	      echo linux ;;
         *-*-openbsd*)         echo openbsd ;;
         *-*-freebsd*)         echo freebsd ;;