windows: use upper() instead of lower() or os.path.normcase() this patch uses upper() instead of lower() or os.path.normcase() for case folding on Windows(NTFS), because lower-ing causes problems for some languages on it. see below for detail about problem of lower-ing: https://blogs.msdn.com/b/michkap/archive/2005/01/16/353873.aspx

icasefs: avoid normcase()-ing in util.fspath() for efficiency 'dirstate._normalize()', the only caller of 'util.fspath()', has already normcase()-ed path before invocation of it. normcase()-ed root can be cached on dirstate side, too. so, this patch changes 'util.fspath()' API specification to avoid normcase()-ing in it.

icasefs: use util.normcase() instead of lower() or os.path.normcase in fspath this also avoids lower()-ing on each path components by reuse the path normcase()-ed at beginning of function.