Avoid producing symbols for symlinks and directory names that just happen to have the particular suffix

OBS-URL: https://build.opensuse.org/package/show/windows:mingw:win64/mingw64-filesystem?expand=0&rev=66

mingw64-find-provides.sh

@@ -17,16 +17,19 @@ pcs=$(echo $filelist | tr [:blank:] '\n' | grep '\.pc$')
 implibs=$(echo $filelist | tr [:blank:] '\n' | grep '\.a$')
 
 for f in $dlls; do
+    [ ! -f "$f" ] && continue
     basename=`basename $f | tr [:upper:] [:lower:]`
     echo "mingw64($basename)"
 done
 
 for g in $pcs; do
+    [ ! -f "$g" ] && continue
     dirname=`dirname $g`
 	PKG_CONFIG_PATH=$dirname x86_64-w64-mingw32-pkg-config --print-errors --print-provides $g | awk '{ print "mingw64(pkg:"$1")", $2, $3 }'
 done | sort -u
 
 for h in $implibs; do
+    [ ! -f "$h" ] && continue
     libname=`basename $h | sed 's#^lib##g' | sed 's#\.dll\.#\.#g' | sed 's#\.a##g'`
 	echo "mingw64(lib:$libname)"
 done