[SystemZ] Add NRK, ORK and XRK

The atomic tests assume the two-operand forms, so I've restricted them to z10.

Running and-01.ll, or-01.ll and xor-01.ll for z196 as well as z10 shows why
using convertToThreeAddress() is better than exposing the three-operand forms
first and then converting back to two operands where possible (which is what
I'd originally tried).  Using the three-operand form first stops us from
taking advantage of NG, OG and XG for spills.

llvm-svn: 186683
diff --git a/llvm/test/CodeGen/SystemZ/and-01.ll b/llvm/test/CodeGen/SystemZ/and-01.ll
index f893148..3b230ba 100644
--- a/llvm/test/CodeGen/SystemZ/and-01.ll
+++ b/llvm/test/CodeGen/SystemZ/and-01.ll
@@ -1,6 +1,7 @@
 ; Test 32-bit ANDs in which the second operand is variable.
 ;
-; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+; RUN: llc < %s -mtriple=s390x-linux-gnu -mcpu=z10 | FileCheck %s
+; RUN: llc < %s -mtriple=s390x-linux-gnu -mcpu=z196 | FileCheck %s
 
 declare i32 @foo()