use cygpath to sanitize

Author: wtdcode

qemu/configure

@@ -200,6 +200,9 @@ source_path=$(cd "$(dirname -- "$0")"; pwd)
 
 # Avoid having D:\ in $PWD under MinGW.
 PWD=$(pwd)
+if command -v cygpath >/dev/null 2>&1; then
+  PWD=$(cygpath -u "$PWD")
+fi
 if printf %s\\n "$source_path" "$PWD" | grep -q "[[:space:]:]";
 then
   error_exit "main directory $source_path or $PWD cannot contain spaces nor colons"