MSVC build in Win95/Cygwin - changes to 1.2.1 source required

[Gerald W. Shapiro]

These are the changes I had to make to the gprolog-1.2.1 distribution in
order to get a successful compile using the --with-msvc option.

1. Delete the definition of stat in src\EnginePl\arch_dep.h
(It is already defined in an MSVC header)

2. Line 154 of cpp_headers.c add a do-nothing line after #endif (I added
i=0 ; ) to stop msvc from complaining about a missing semi-colon.

3. In src/EnginePl/Makefile.in replace $(ROOT_DIR)/src/$$i with ../$$i
(windows has trouble with the full cygwin path, but relative paths are ok)

4. In src/Fd2c/compile.pl , line 511, change reg_alloc to reg_alloc.pl

ciao,

Gerald