ARM64: disable printing of "lslv" type aliases

You can write "lslv w0, w1, w2" (probably for legacy reasons), but it should be
printed as simply "lsl".

This will be tested when the TableGen "should I print this Alias" heuristic is
fixed (very soon).
ARM64: give NEG priority over SUB when printing aliases.

For example, the full instruction "sub w0, wzr, w1, uxtw" could print as either
"neg w0, w1" or "sub w0, wzr, w1". The former is better.

This will be tested when the TableGen "should I print this Alias" heuristic is
fixed (very soon).
ARM64: give MOV priority over shorter ORR when printing aliases.

MOV is almost always the right thing to print if possile. People understand it.

This will be tested when the TableGen "should I print this Alias" heuristic is
fixed (very soon).
ARM64: give TST aliases priority over ANDS.

If an ANDS instruction has Rd == ZR it should be printed as TST since
its only effect is on the flags register NZCV.

This will be tested when the TableGen "should I print this Alias"
heuristic is fixed (very soon).
ARM64: disable printing of LDUR -> LDR aliases

We accept "ldr w3, [x1, #-1]" as a convenience, but we should still print the
canonical "ldur" form.

This will be tested when the TableGen "should I print this Alias" heuristic is
fixed (very soon).
ARM64: disable printing of swapped compare-mask aliases

You can perform (say) an fcmle operation by swapping the operands on an fcmge,
but it shouldn't be printed like that.

This will be tested when the TableGen "should I print this Alias" heuristic is
fixed (very soon).
AArch64: disable printing of MOV -> MOVZ aliases

Actually, MOV sometimes is canonical, but for now this is a better
approximation than what's there.

This will be tested when the TableGen "should I print this Alias" heuristic is
fixed (very soon).
X86: disable printing of bare "mov" aliases

In AT&T syntax, we should probably print the full "movl" or "movw". TableGen
used to ignore these aliases because it was miscounting the number of operands.
This fixes the issue.

This will be tested when the TableGen "should I print this Alias"
heuristic is fixed (very soon).
Mips: don't print subu alias for addiu

Certainly not without having a custom PrintMethod to invert the immediate
beforehand. But probably not at all.

This will be tested when the TableGen "should I print this Alias" heuristic is
fixed (very soon).
Sparc: disable printing on longer "brX,pt" aliases

This will be tested when the TableGen "should I print this Alias" heuristic is
fixed (very soon).
Sparc: disable printing of jmp/call aliases (C++ does it)

These aliases are handled entirely in C++ and only having TableGen InstAliases
for some of them was confusing LLVM.

This will be tested when the TableGen "should I print this Alias" heuristic is
fixed (very soon).
AArch64: disable printing of add/sub alias

This alias appears not to have an appropriate PrintMethod. Normally, I'd look
into it, but since AArch64 is disappearing soon it's probably not worth it.

This will be tested when the TableGen "should I print this Alias" heuristic is
fixed (very soon).