Chris Lattner 12adbeb872 Prepare for implementation of TensorFlow passes: ... - Sketch out a TensorFlow/IR directory that will hold op definitions and common TF support logic. We will eventually have TensorFlow/TF2HLO, TensorFlow/Grappler, TensorFlow/TFLite, etc. - Add sketches of a Switch/Merge op definition, including some missing stuff like the TwoResults trait. Add a skeleton of a pass to raise this form. - Beef up the Pass/FunctionPass definitions slightly, moving the common code out of LoopUnroll.cpp into a new IR/Pass.cpp file. - Switch ConvertToCFG.cpp to be a ModulePass. - Allow _ to start bare identifiers, since this is important for TF attributes. PiperOrigin-RevId: 206502517		2019-03-29 12:47:25 -07:00
mlir	Prepare for implementation of TensorFlow passes:	2019-03-29 12:47:25 -07:00