merge revision(s) r43583: [Backport #9288]

	* file.c (GetLastError): already defined in windows.h on nowadays
	  cygwin, and caused the confliction with the system provided
	  definition on cygwin64.  by @kou1okada [Fixes GH-433].


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@44905 b2dd03c8-39d4-4d8f-98ff-823fe69b080e