[FastISel][AArch64] Add MachO large code model support for function calls.

Currently the large code model for MachO uses the GOT to make function calls.
Emit the required adrp and ldr instructions to load the address from the GOT.

Related to <rdar://problem/17733076>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214381 91177308-0d34-0410-b5e6-96231b3b80d8
[FastISel][AArch64] Update and enable patchpoint and stackmap intrinsic tests for FastISel.

This commit updates the existing SelectionDAG tests for the stackmap and patchpoint
intrinsics and enables FastISel testing. It also splits up the tests into separate
files, due to different codegen between SelectionDAG and FastISel.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214382 91177308-0d34-0410-b5e6-96231b3b80d8
Fix some grammatical errors.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214383 91177308-0d34-0410-b5e6-96231b3b80d8
InstSimplify: Simplify (X - (0 - Y)) if the second sub is NUW

If the NUW bit is set for 0 - Y, we know that all values for Y other
than 0 would produce a poison value.  This allows us to replace (0 - Y)
with 0 in the expression (X - (0 - Y)) which will ultimately leave us
with X.

This partially fixes PR20189.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214384 91177308-0d34-0410-b5e6-96231b3b80d8
InstCombine: Correctly propagate NSW/NUW for x-(-A) -> x+A

We can only propagate the nsw bits if both subtraction instructions are
marked with the appropriate bit.

N.B.  We only propagate the nsw bit in InstCombine because the nuw case
is already handled in InstSimplify.

This fixes PR20189.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214385 91177308-0d34-0410-b5e6-96231b3b80d8