6900043: Add method to return line.separator property
Summary: Add System.lineSeparator(), returning getProperty("line.separator")
Reviewed-by: darcy
^build/
^dist/
^nbproject/private/
^src/share/tools/hsdis/build/
^src/share/tools/IdealGraphVisualizer/[a-zA-Z0-9]*/build/
^src/share/tools/IdealGraphVisualizer/build/
^src/share/tools/IdealGraphVisualizer/dist/