Print out what the assembler is doing to figure out why it's not working.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65854 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

Makefile.in

@@ -407,6 +407,7 @@ $(srcdir)/enc/jis/props.h: enc/jis/props.kwd
 .s.@OBJEXT@:
 	@$(ECHO) assembling $<
 	$(MAKEDIRS) $(@D)
+	@$(ECHO) $(Q) $(AS) $(ASFLAGS) -o $@ $<
 	$(Q) $(AS) $(ASFLAGS) -o $@ $<
 
 .c.S: