Add aliases for VAND imm to VBIC ~imm

On ARM NEON, VAND with immediate (16/32 bits) is an alias to VBIC ~imm with
the same type size. Adding that logic to the parser, and generating VBIC
instructions from VAND asm files.

This patch also fixes the validation routines for NEON splat immediates which
were wrong.

Fixes PR20702.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218450 91177308-0d34-0410-b5e6-96231b3b80d8
[mips] Add CCValAssign::[ASZ]ExtUpper and CCPromoteToUpperBitsInType and handle struct's correctly on big-endian N32/N64 return values.

Summary:
The N32/N64 ABI's require that structs passed in registers are laid out
such that spilling the register with 'sd' places the struct at the lowest
address. For little endian this is trivial but for big-endian it requires
that structs are shifted into the upper bits of the register.

We also require that structs passed in registers have the 'inreg'
attribute for big-endian N32/N64 to work correctly. This is because the
tablegen-erated calling convention implementation only has access to the
lowered form of struct arguments (one or more integers of up to 64-bits
each) and is unable to determine the original type.

Reviewers: vmedic

Reviewed By: vmedic

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5286

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218451 91177308-0d34-0410-b5e6-96231b3b80d8