AArch64/ARM64: implement "mov $Rd, $Imm" aliases in TableGen.

This is a slightly different approach to AArch64 (the base instruction
definitions aren't quite right for that to work), but achieves the
same thing and reduces C++ hackery in AsmParser.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208605 91177308-0d34-0410-b5e6-96231b3b80d8
AArch64/ARM64: use InstAliases for NEON logical (imm) instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208606 91177308-0d34-0410-b5e6-96231b3b80d8
TableGen: use PrintMethods to print more aliases

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208607 91177308-0d34-0410-b5e6-96231b3b80d8
DwarfDebug: Avoid an extra map lookup while constructing abstract scope DIEs and reduce nesting/conditionals.

One test case had to be updated as it still had the extra indirection
for the variable list - removing the extra indirection got it back to
passing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208608 91177308-0d34-0410-b5e6-96231b3b80d8