AArch64/ARM64: use HS instead of CS & LO instead of CC.

On instructions using the NZCV register, a couple of conditions have dual
representations: HS/CS and LO/CC (meaning unsigned-higher-or-same/carry-set and
unsigned-lower/carry-clear). The first of these is more descriptive in most
circumstances, so we should print it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207644 91177308-0d34-0410-b5e6-96231b3b80d8
AArch64/ARM64: expunge CPSR from the sources

AArch64 does not have a CPSR register in the same way that AArch32 does. Most
of its compiler-relevant roles have been taken over by the more specific NZCV
register (representing just the flags set by normal instructions).

Its system control functions still remain, but are now under the
pseudo-register referred to as "PSTATE". They're accessed via various MRS & MSR
instructions described in the reference manual.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207645 91177308-0d34-0410-b5e6-96231b3b80d8
AArch64/ARM64: copy support for bCC instead of b.CC across.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207646 91177308-0d34-0410-b5e6-96231b3b80d8
AArch64/ARM64: allow smaller granule relocations on MOVZ/MOVN

Testing will be enabled shortly with basic-a64-instructions.s

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207647 91177308-0d34-0410-b5e6-96231b3b80d8
ARM64: use 32-bit operations for uxtb & uxth

Testing will be enabled shortly with basic-a64-instructions.s

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207648 91177308-0d34-0410-b5e6-96231b3b80d8
ARM64: print lsr instead of lsrv for variable shifts (etc)

The canonical syntax for shifts by a variable amount does not end with 'v', but
that syntax should be supported as an alias (presumably for legacy reasons).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207649 91177308-0d34-0410-b5e6-96231b3b80d8
ARM64: enable AArch64's basic-a64-instructions test

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207650 91177308-0d34-0410-b5e6-96231b3b80d8