Change the OS interface layer to use traditional direct function call

implementations instead of the more complicated virtual function table.
Omit the asynchronous I/O demo. (CVS 2870)

FossilOrigin-Name: 2529c2e11fa1d345ec61f647e4f6fae20a7133d6

main.mk

@@ -133,15 +133,12 @@ TESTSRC = \
   $(TOP)/src/test4.c \
   $(TOP)/src/test5.c \
   $(TOP)/src/test6.c \
-  $(TOP)/src/test_async.c \
   $(TOP)/src/utf.c \
   $(TOP)/src/util.c \
   $(TOP)/src/vdbe.c \
   $(TOP)/src/md5.c \
   $(TOP)/src/where.c
 
-#  $(TOP)/src/test_async.c 
-
 # Header files used by all library source files.
 #
 HDR = \
@@ -358,7 +355,8 @@ tclsqlite3:	$(TOP)/src/tclsqlite.c libsqlite3.a
 		$(TOP)/src/tclsqlite.c libsqlite3.a $(LIBTCL) $(THREADLIB)
 
 testfixture$(EXE):	$(TOP)/src/tclsqlite.c libsqlite3.a $(TESTSRC)
-	$(TCCX) $(TCL_FLAGS) -DTCLSH=1 -DSQLITE_TEST=1 -o testfixture$(EXE) \
+	$(TCCX) $(TCL_FLAGS) -DTCLSH=1 -DSQLITE_TEST=1 -DSQLITE_CRASH_TEST=1 \
+		-o testfixture$(EXE) \
 		$(TESTSRC) $(TOP)/src/tclsqlite.c \
 		libsqlite3.a $(LIBTCL) $(THREADLIB)