[llvm] r209386 - Override runOnMachineFunction for ARMISelDAGToDAG so that we can

[Tim Northover]

> Preparation for something bigger, basically the CGContext stuff from
> another thread. The basic idea comes down to being able to link
> together modules (or include in a single module) functions which
> target different subtargets/subtarget features and still be able to
> codegen and optimize them correctly. It's similar to some of the
> function specific optimization that happened recently.

Oh, excellent! Looking forward to seeing more of that.

Tim.