merge revision(s) 39777: [Backport #8080]

	mingw build fix

	* configure.in: struct timeval is defined in winsock2.h on mingw.

	* include/ruby/missing.h: include time.h for time_t, and sys/time.h
  for timeval and timespec.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39848 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 39779: [Backport #8080]

	Makefile.sub: fix mswin build

	* win32/Makefile.sub (config.h): fix mswin build, also VC has time.h
  and struct timeval.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39849 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 39781,39783: [Backport #8080]

	missing.h: build fix

	* include/ruby/missing.h: include time.h and sys/time.h iff needed,
  but excepct for sys/time.h on linux to get rid of glibc bug.
	* include/ruby/missing.h: removed __linux__. it's unnecessary.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39850 b2dd03c8-39d4-4d8f-98ff-823fe69b080e