-** Make SYNC_INPUT the default. [true since 2008-03-11]
- All loops using immediate_quit need to be checked to ensure that
- C-g can interrupt them, in case of an infinite loop. Once we
- switch to using SYNC_INPUT, we can remove the BLOCK_INPUTs in the
- allocation functions (allocate_string etc.) without worrying about
- data munging.
-