Move RDF from Hexagon to Codegen [1/6]

[sconstab]

Summary

RDF is designed to be target agnostic. Therefore it would be useful to have it available for other targets, such as X86.

[zbrid]

LGTM other than the question about the functionality change.

llvm/lib/CodeGen/RDFGraph.cpp

756

Thanks for this patch! Qq, is this some functionality change? Why does the refactor require this update?

[andrew.w.kaylor]

llvm/lib/CodeGen/RDFGraph.cpp

756

The original RDF implementation didn't need to handle Windows targets. The TLI::getExceptionSelectionRegister() method has an assertion testing that it is not called for Windows EH personality functions. There is no exception selector register on Windows.

[kparzysz]

This obviously looks great to me, but I'll let someone else give the final approval.

[kparzysz]

It looks like @zbrid has already LGTMd this.