'glib/gio/glocalfile.c' no longer compiles with MSVC

[John Emmas <johne53 tiscali co uk>]

I just updated libglib from git and discovered that a new function got 
added to '<glib>/gio/glocalfile.c'.  The new function is called 
g_local_file_measure_size_of_contents() and I think there are a couple 
of other functions supporting it.

g_local_file_measure_size_of_contents() appears to assume a posix 
compliant compiler.  It calls opendir(), readdir() and closedir() and 
therefore cannot be compiled with MSVC.  Maybe there's a #define 
somewhere that I haven't noticed or maybe the function isn't yet 
complete?  Similar functions in the same source file use #ifdef 
G_OS_WIN32 in order to implement alternative functionality for Windows / 
non-Windows - but this doesn't seem to be done yet for 
g_local_file_measure_size_of_contents()

John