Add PSAPI_WORKING_SET_BLOCK and PSAPI_WORKING_SET_INFORMATION, make PSAPI_WORKING_SET_EX_BLOCK and PSAPI_WORKING_SET_EX_INFORMATION available to XP.

git-svn-id: svn+ssh://svn.code.sf.net/p/mingw-w64/code/trunk@4065 4407c894-4637-0410-b4f5-ada5f102cad1