Stop creating ripper.h because it's not used

ext/ripper/depend

@@ -12,7 +12,7 @@ ripper.o: ripper.c
 
 .y.c:
 	$(ECHO) compiling compiler $<
-	$(Q) $(BISON) -t -v -o$@ -h$*.h - $< < $<
+	$(Q) $(BISON) -t -v -o$@ - $< < $<
 
 all: check
 static: check

ext/ripper/extconf.rb

@@ -6,7 +6,7 @@ require 'rbconfig'
 
 def main
   $objs = %w(eventids1.o eventids2.o ripper.o ripper_init.o)
-  $distcleanfiles.concat %w(ripper.y ripper.c ripper.h eventids1.c eventids1.h eventids2table.c ripper_init.c)
+  $distcleanfiles.concat %w(ripper.y ripper.c eventids1.c eventids1.h eventids2table.c ripper_init.c)
   $cleanfiles.concat %w(ripper.E ripper.output y.output .eventids2-check)
   $defs << '-DRIPPER'
   $defs << '-DRIPPER_DEBUG' if $debug