Add -D__ASSEMBLER__ to compile.S so that -std=c99 would not fail

Makerules

@@ -93,7 +93,7 @@ disp_ar        = $($(DISP)_disp_ar)
 disp_ld        = $($(DISP)_disp_ld)
 
 cmd_compile.c = $(CC) -c $< -o $@ $(CFLAGS) $(ARCH_CFLAGS) $(CFLAGS-$(suffix $@)) $(filter-out $(CFLAGS-OMIT-$(notdir $<)),$(CFLAGS-$(notdir $(^D)))) $(CFLAGS-$(subst $(top_srcdir),,$(dir $<))) $(CFLAGS-$(notdir $<)) $(CFLAGS-$(notdir $@))
-cmd_compile.S = $(cmd_compile.c) $(ASFLAGS) $(ARCH_ASFLAGS) $(ASFLAGS-$(suffix $@)) $(ASFLAGS-$(notdir $<)) $(ASFLAGS-$(notdir $@))
+cmd_compile.S = $(cmd_compile.c) -D__ASSEMBLER__ $(ASFLAGS) $(ARCH_ASFLAGS) $(ASFLAGS-$(suffix $@)) $(ASFLAGS-$(notdir $<)) $(ASFLAGS-$(notdir $@))
 cmd_compile.m = $(cmd_compile.c) -DL_$(patsubst %$(suffix $(notdir $@)),%,$(notdir $@))
 cmd_compile-m = $(CC) $^ -c -o $@ $(CFLAGS) $(ARCH_CFLAGS) $(CFLAGS-$(suffix $@)) $(CFLAGS-$(notdir $(@D))) $(CFLAGS-$(notdir $@))
 cmd_strip     = $(STRIPTOOL) $(STRIP_FLAGS) $^