Add 'nocona' to the list of Intel ia64 CPUs and k8 to the AMD CPUs.

Replace -fmemoize-lookups -fsave-memoized with a working example,
-fconserve-space.  To quote part of the GCC docs on this option:

"Put uninitialized or runtime-initialized global variables into the
common segment, as C does."

MFC after:	2 days
Submitted by:	Daniel Gerzo <danger@rulez.sk> (original version)

share/examples/etc/make.conf

@@ -31,12 +31,12 @@
 # Currently the following CPU types are recognized:
 #   Intel x86 architecture:
 #       (AMD CPUs)	opteron athlon64 athlon-mp athlon-xp athlon-4
-#			athlon-tbird athlon k6-3 k6-2 k6 k5
+#			athlon-tbird athlon k8 k6-3 k6-2 k6 k5
 #       (Intel CPUs)	pentium4[m] pentium3[m] pentium2 penitumpro pentium-mmx
 #			pentium i486 i386
 #   Alpha/AXP architecture: ev67 ev6 pca56 ev56 ev5 ev45 ev4
 #   AMD64 architecture: opteron, athlon64, nocona
-#   Intel ia64 architecture: itanium
+#   Intel ia64 architecture: itanium nocona
 #
 # (?= allows to buildworld for a different CPUTYPE.)
 #
@@ -59,7 +59,7 @@
 # to add to CXXFLAGS value, "+=" must be used rather than "=".  Using "="
 # alone will remove the often needed contents of CFLAGS from CXXFLAGS.
 #
-#CXXFLAGS+= -fmemoize-lookups -fsave-memoized
+#CXXFLAGS+= -fconserve-space
 #
 # MAKE_SHELL controls the shell used internally by make(1) to process the
 # command scripts in makefiles.  Three shells are supported, sh, ksh, and