[COFF, ARM64] Add CodeView register mapping

CodeView has its own register map which is defined in cvconst.h. Missing this
mapping before saving register to CodeView causes debugger to show incorrect
value for all register based variables, like variables in register and local
variables addressed by register (stack pointer + offset).

This change added mapping between LLVM register and CodeView register so the
correct register number will be stored to CodeView/PDB, it aso fixed the
mapping from CodeView register number to register name based on current
CPUType but print PDB to yaml still assumes X86 CPU and needs to be fixed.

Differential Revision: https://reviews.llvm.org/D62608

llvm-svn: 362280