soc/runtime: fix DDS reset
soc/rtio: software-controlled replace
soc/rtio: mini-channels
soc/ad9858: do not drive FUD by default
soc/target: connect FUD to RTIO
py2llvm/fractions: fix addsub with int
runtime: add rtio_replace syscall
rtio: support readout of counter from software
devices: new RTIO driver
runtime: support real-time FUD
runtime: increase initial time

This leaves some time for DDS FUD operations to complete.
devices/dds_core: support realtime FUD and zero-length pulse collapsing
runtime: support arbitrarily long initial DDS setup time
rtio: remove ISE bug workaround
py2llvm: support pass statements
transforms/inline: support for function return values
transforms/inline: refactor and fix _ReferenceManager.inline
language/core: remove kernel_attr_ro
Consistent variable naming
devices/rtio_core: add dummy counter