Switch CPU names not recognized by GNU assembler
Switch CPU names not recognized by GNU assembler to a close CPU that it
does recognize. In this patch, kryo, falkor and saphira all get
replaced by cortex-a57 when invoking the assembler. In addition, krait
was already being replaced by cortex-a15.
Subscribers: srhines, cfe-commits
Differential Revision: https://reviews.llvm.org/D40476