cw: give cw(1onbld) a new interface allowing for multiple arbitrary shadows

*** 55,66 ****
  sysevent/tst.post.exe := LDLIBS += -lsysevent
  sysevent/tst.post_chan.exe := LDLIBS += -lsysevent
  
  ustack/tst.bigstack.exe := COPTFLAG += -xO1
  
- GCC = $(ONBLD_TOOLS)/bin/$(MACH)/cw -_gcc
- 
  nfs/%.o: $(SNOOPDIR)/%.c
          $(COMPILE.c) -o $@ $< -I$(SNOOPDIR)
          $(POST_PROCESS_O)
  nfs/tst.call.exe: nfs/tst.call.o nfs/$(SNOOPOBJS)
          $(LINK.c) -o $@ nfs/tst.call.o nfs/$(SNOOPOBJS) $(LDLIBS) -lnsl
--- 55,64 ----
*** 73,86 ****
  nfs/tst.call3.exe: nfs/tst.call3.o nfs/$(RPCSVCOBJS)
          $(LINK.c) -o $@ nfs/tst.call3.o nfs/$(RPCSVCOBJS) \
          $(LDLIBS) -lnsl -lrpcsvc
          $(POST_PROCESS) ; $(STRIP_STABS)
  
- pid/tst.gcc.exe: pid/tst.gcc.c
-         $(GCC) -o pid/tst.gcc.exe pid/tst.gcc.c $(LDFLAGS) $(LDLIBS)
-         $(POST_PROCESS) ; $(STRIP_STABS)
- 
  json/tst.usdt.o: json/usdt.h
  
  json/usdt.h: json/usdt.d
          $(DTRACE) -h -s json/usdt.d -o json/usdt.h
  
--- 71,80 ----