Fix PR10104 by adding a bounds check on a vector element access check. It was

Fix PR10104 by adding a bounds check on a vector element access check. It was
assuming that all offsets are legal vector accesses, and thus trying to access
the float member of { <2 x float>, float } as the 3rd element of the first
member.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132766 91177308-0d34-0410-b5e6-96231b3b80d8