SelectionDAG: Use correct pointer size when lowering function arguments v2

This adds minimal support to the SelectionDAG for handling address spaces
with different pointer sizes.  The SelectionDAG should now correctly
lower pointer function arguments to the correct size as well as generate
the correct code when lowering getelementptr.

This patch also updates the R600 DataLayout to use 32-bit pointers for
the local address space.

v2:
  - Add more helper functions to TargetLoweringBase
  - Use CHECK-LABEL for tests

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189221 91177308-0d34-0410-b5e6-96231b3b80d8
R600: Add support for v4i32 and v2i32 local stores

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189222 91177308-0d34-0410-b5e6-96231b3b80d8
R600: Add support for i8 and i16 local memory stores

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189223 91177308-0d34-0410-b5e6-96231b3b80d8
SelectionDAG: Use correct pointer size when splitting vector stores

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189224 91177308-0d34-0410-b5e6-96231b3b80d8
R600: Add support for i8 and i16 local memory loads

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189225 91177308-0d34-0410-b5e6-96231b3b80d8
R600: Add support for vector local memory loads

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189226 91177308-0d34-0410-b5e6-96231b3b80d8
SelectionDAG: Remove unnecessary uses of TargetLowering::getPointerTy()

If we have a binary operation like ISD:ADD, we can set the result type
equal to the result type of one of its operands rather than using
TargetLowering::getPointerTy().

Also, any use of DAG.getIntPtrConstant(C) as an operand for a binary
operation can be replaced with:
DAG.getConstant(C, OtherOperand.getValueType());

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189227 91177308-0d34-0410-b5e6-96231b3b80d8