8294368: Java incremental builds broken on Windows after JDK-8293116

Reviewed-by: erikj, djelinski, jlahoda

make/scripts/fixpath.sh

@@ -352,6 +352,21 @@ function convert_path() {
   fi
 }
 
+# Treat $1 as name of a file containing paths. Convert those paths to Windows style,
+# and output them to the file specified by $2.
+# If the output file already exists, it is overwritten.
+function convert_file() {
+  infile="$1"
+  outfile="$2"
+  if [[ -e $outfile ]] ; then
+    rm $outfile
+  fi
+  while read line; do
+    convert_path "$line"
+    echo "$result" >> $outfile
+  done < $infile
+}
+
 # Treat $1 as name of a file containing paths. Convert those paths to Windows style,
 # in a new temporary file, and return a string "@<temp file>" pointing to that
 # new file.
@@ -498,6 +513,8 @@ if [[ "$ACTION" == "import" ]] ; then
 elif [[ "$ACTION" == "print" ]] ; then
   print_command_line "$@"
   echo "$result"
+elif [[ "$ACTION" == "convert" ]] ; then
+  convert_file "$@"
 elif [[ "$ACTION" == "exec" ]] ; then
   exec_command_line "$@"
   # Propagate exit code