Discuss about the LLVM SW mitigation to Jump Conditional Code Erratum

I will reply those comments tomorrow.

Annita, do you have measurements with inserting NOPs instead of redundant segment prefixes. The code review was asking for performance data to show that prefixes are better than NOPs.

Also -ffunction-sections. With more sections, it may be easier to
exhibit non-convergence problems. The compile time may not be slowed
much because functions will be smaller. The code size may increase if
more sections need over-alignment.

Yes, we will test it. I think -ffunction-sections will increase the section numbers, but not the function numbers. The code size may be increased because every code section has to be aligned with 32-byte for the padding.