Merge upstream LLVM r182803:

  [Mips] Add Mips specific dynamic table entry tags.

This is to support an upcoming LLDB snapshot update.

Reviewed by:	dim@
Sponsored by:	DARPA, AFRL
Merge upstream LLVM r192118:

  Formally added an explicit enum for DWARF TLS support. No functionality
  change.

Reviewed by:	dim@
Sponsored by:	DARPA, AFRL