* random.c (rb_memhash): use siphash.

	* siphash.c (sip_init_state): use union to suppress warnings by gcc
	  4.7.

	* siphash.h: include inttypes.h only when HAVE_INTTYPES_H is defined.

	* siphash.h: check configure macros before include newer headers.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@37600 b2dd03c8-39d4-4d8f-98ff-823fe69b080e