Added comments to indicate what options are required to take advantage

of removal of unused function code found in newer binutils/egcs
snapshots.  Early test with psim and hello.exe showed about a 13%
gain.

make/custom/psim.cfg

@@ -71,7 +71,8 @@ endef
 #  This contains the compiler options necessary to select the CPU model
 #  and (hopefully) optimize for it. 
 #
-CPU_CFLAGS = -mcpu=603
+CPU_CFLAGS = -mcpu=603 
+#-ffunction-sections
 
 # optimize flag: typically -0, could use -O4 or -fast
 # -O4 is ok for RTEMS
@@ -104,6 +105,7 @@ define make-exe
 	$(SIZE) $@
 endef
 else
+# -Wl,--gc-sections
 define make-exe
 	$(CC) $(CFLAGS) -o $(basename $@).exe \
 	    $(LINK_OBJS) $(LINK_LIBS)