R600: Add a testcase for sext_in_reg I missed.

This sext_inreg i32 in i64 case was already handled, but not enabled.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204840 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed