INT 21,60 - Get Fully Qualified File Name (Undocumented 3.x+)

	AH = 60h
	DS:SI = pointer to ASCIIZ string containing unqualified filename
	ES:DI = pointer to 128 byte buffer to contain fully qualified filename

	on return:
	ES:DI = address of fully qualified filename string
	AH = error code if CF set

	- undocumented, available in DOS 3.x+
	- does not check for file existence, simple provides a fully
	  qualified filename for the given filespec
	- this function ignores ASSIGN'ed, JOIN'ed, SUBST'ed and network
	  redirections and returns the true path name
	- returned string is in upper case and has forward slashes replaced
	  by back slashes;  filename always begins with "d:" or "\\" format
	- AL register is destroyed
	- supported by OS/2 1.1 compatibility box