Check whether a pointer is non-null (isKnownNonNull) in isKnownNonZero.

This handles the case where we have an inbounds GEP with alloca as the pointer.
This fixes the regression in PR12750 and rdar://13286434.
Note that we can also fix this by handling some GEP cases in isKnownNonNull.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177321 91177308-0d34-0410-b5e6-96231b3b80d8
Annotate X86 arithmetic instructions with SchedRW lists.

This new-style scheduling information is going to replace the
instruction iteneraries.

This also serves as a test case for Andy's fix in r177317.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177323 91177308-0d34-0410-b5e6-96231b3b80d8