Delete code related to NATIVETRAN feature. (#232)

* Delete code related to NATIVETRAN feature.

This was obsolete work that had been done for generating
native code from the bytecode.

Closes Interlisp/medley#89.

* Remove unused SaveD6.

bin/compile-flags

@@ -30,7 +30,6 @@ NOASM		If true, suppress any attempt to include assembler
 			SUN3_OS4_IL
 			SUN4_OS4_IL
 			OPDISP
-			NATIVETRAN
 			PROFILE
 		and enables NOASMFNCALL
 C_ONLY
@@ -101,9 +100,6 @@ ORG_FILPCORSORBAR If true, you get the pixwin version of cursor changing;
 		region.
 OLD_CURSOR	If true, uses the pixwin cursor code (e.g., win_setcursor);
 		otherwise, uses the direct-write technique.
-NATIVETRAN	If true, code to support the native-code translator is
-		included in the emulator.  This feature was never released,
-		and most such code is probably obsolete.
 OS4_TYPE4BUG	If true, includes the patches around SunOS 4.0.x's failure
 		to tell you you've got a Type-4 keyboard.
 ALLDIRSEARCH	CURRENTLY HARD DISABLED IN directory.c; looks like it 

bin/makefile-tail

@@ -39,7 +39,6 @@
 #INSDIR = $(RELDIR)install.$(RELEASENAME)/
 CHKDIR = $(RELDIR)checksumdir/
 SCRPTDIR = $(RELDIR)scripts/
-NATDIR = $(RELDIR)usernative/
 
 # OSARCHDIR is the os/architecture dir, where executables all go.
 OSARCHDIR = ../$(OSARCHNAME)/
@@ -893,7 +892,6 @@ $(OBJECTDIR)lpy.tab.o : $(SRCDIR)lpy.tab.c  $(REQUIRED-INCS) $(INCDIR)lpdefs.h $
 # Installation targets - copyprotect is ON here
 # library, sysouts, fonts on release directories not handled here.
 # userfiles are separate target explicitly (can make w/o building lde)
-#    $(NATDIR)native.h $(NATDIR)disp68K.il
 ################################################################################
 
 prerelease :
@@ -975,18 +973,6 @@ $(SCRPTDIR)medley : $(BINDIR)medley
 	cp -p $(BINDIR)medley $(SCRPTDIR)medley
 	chmod 755 $(SCRPTDIR)medley
 
-################################################################################
-# Obsolete
-################################################################################
-
-$(NATDIR)native.h : $(INCDIR)native.h
-	rm -f $(NATDIR)native.h
-	ln -s $(INCDIR)native.h $(NATDIR)native.h
-
-$(NATDIR)disp68K.il : $(SRCDIR)disp68K.il
-	rm -f $(NATDIR)disp68K.il
-	ln -s $(SRCDIR)disp68K.il $(NATDIR)disp68K.il
-
 ################################################################################
 # Miscellaneous targets
 #	 .c.s. should always have -O