Break stdio/asprintf.c and misc/uchar.c into pieces, one function
per compilation unit:
	* stdio/vasprintf.c: New.
	* misc/uchar_c16rtomb.c: New.
	* misc/uchar_c32rtomb.c: New.
	* misc/uchar_mbrtoc16.c: New.
	* misc/uchar_mbrtoc32.c: New.
	* Makefile.am: Adjust.
	* Makefile.in: Regenerate.


git-svn-id: svn+ssh://svn.code.sf.net/p/mingw-w64/code/trunk@4567 4407c894-4637-0410-b4f5-ada5f102cad1