patch 9.1.0449: MS-Windows: Compiler warnings

Problem:  MS-Windows: Compiler warnings
Solution: Resolve size_t to int warnings

closes: #14874

A couple of warnings in ex_docmd.c have been resolved by modifying their
function argument types, followed by some changes in various function
call sites.  This also allowed removal of some casts to cope with
size_t/int conversion.

Signed-off-by: Mike Williams <mrmrdubya@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/if_cscope.c b/src/if_cscope.c
index d9982ef..7b6fd92 100644
--- a/src/if_cscope.c
+++ b/src/if_cscope.c
@@ -541,7 +541,7 @@
     char	*ppath = NULL;
     int		i;
     int		len;
-    int		usedlen = 0;
+    size_t	usedlen = 0;
     char_u	*fbuf = NULL;
 
     // get the filename (arg1), expand it, and try to stat it