Fix assertion in CreateBitcast following SROA logic

[Daniel Sanders via llvm-commits]

Could you add a testcase?

> -----Original Message-----
> From: llvm-commits [mailto:llvm-commits-bounces at lists.llvm.org] On Behalf
> Of Pedro Ferreira via llvm-commits
> Sent: 07 December 2015 11:21
> To: llvm-commits at lists.llvm.org
> Subject: Fix assertion in CreateBitcast following SROA logic
> 
> Hi all,
> 
> The attached patch fixes an assertion we triggered in the BitCast
> constructor when SROA tried to bitcast a pointer across namespaces.
> Instead, check if the type being cast crosses namespaces and use the
> appropriate call.