SelectionDAG: If llvm.donothing has a landingpad, we should clear
CurrentCallSite to avoid an assertion failure:
assert(MMI.getCurrentCallSite() == 0 && "Overlapping call sites!");

rdar://problem/13228754


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176154 91177308-0d34-0410-b5e6-96231b3b80d8
IR: Don't constant fold GEP bitcasts between different address spaces

PR15262 reported a bug where the following instruction:

  i8 getelementptr inbounds i8* bitcast ([4 x i8] addrspace(12)* @buf to i8*),
                                i32 2

was getting folded into:

  addrspace(12)* getelementptr inbounds ([4 x i8] addrspace(12)* @buf, i32 0,
                                        i32 2)

This caused instcombine to crash because the original instruction and
the folded instruction have different types.  The issue was fixed by
disallowing bitcasts between different address spaces to be folded away.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176156 91177308-0d34-0410-b5e6-96231b3b80d8