6648 illumos build should be explicit about C standards

*** 92,102 ****
  install:        $(INSTALL_DEPS)
  
  $(BINARY):      $(OBJS_DIR)/asm10k $(DSP_HDRS)
  
  $(ASM10K):      $(DSP_SRCDIR)/asm10k.c
!         $(CC) -o $@ $(DSP_SRCDIR)/asm10k.c
  
  $(DSP_HDRS): $(ASM10K) $(DSP_SRCS)
          $(CPP) -D$(MODEL10K) -I$(DSP_SRCDIR) $(DSP_SRCDIR)/emu10k.dsp | \
          $(OBJS_DIR)/asm10k $(ASM10KFLAGS) -h $@
  
--- 92,102 ----
  install:        $(INSTALL_DEPS)
  
  $(BINARY):      $(OBJS_DIR)/asm10k $(DSP_HDRS)
  
  $(ASM10K):      $(DSP_SRCDIR)/asm10k.c
!         $(NATIVECC) $(NATIVE_CFLAGS) -o $@ $(DSP_SRCDIR)/asm10k.c
  
  $(DSP_HDRS): $(ASM10K) $(DSP_SRCS)
          $(CPP) -D$(MODEL10K) -I$(DSP_SRCDIR) $(DSP_SRCDIR)/emu10k.dsp | \
          $(OBJS_DIR)/asm10k $(ASM10KFLAGS) -h $@