[ARM] Add missing pseudo-instruction for Thumb1 RSBS.

Shows up rarely for 64-bit arithmetic, more frequently for the compare
patterns added in r325323.

Differential Revision: https://reviews.llvm.org/D53848

llvm-svn: 345782
diff --git a/llvm/test/CodeGen/Thumb/branchless-cmp.ll b/llvm/test/CodeGen/Thumb/branchless-cmp.ll
index 8435529..ed34d63 100644
--- a/llvm/test/CodeGen/Thumb/branchless-cmp.ll
+++ b/llvm/test/CodeGen/Thumb/branchless-cmp.ll
@@ -20,8 +20,7 @@
 ; CHECK-LABEL: test1b:
 ; CHECK-NOT: b{{(ne)|(eq)}}
 ; CHECK:       subs    r1, r0, r1
-; CHECK-NEXT:  movs    r0, #0
-; CHECK-NEXT:  subs    r0, r0, r1
+; CHECK-NEXT:  rsbs    r0, r1, #0
 ; CHECK-NEXT:  adcs    r0, r1
 }
 
@@ -33,8 +32,7 @@
 ; CHECK-LABEL: test2a:
 ; CHECK-NOT: b{{(ne)|(eq)}}
 ; CHECK:       subs    r1, r0, r1
-; CHECK-NEXT:  movs    r0, #0
-; CHECK-NEXT:  subs    r0, r0, r1
+; CHECK-NEXT:  rsbs    r0, r1, #0
 ; CHECK-NEXT:  adcs    r0, r1
 }
 
@@ -71,8 +69,7 @@
 ; CHECK-LABEL: test3b:
 ; CHECK-NOT: b{{(ne)|(eq)}}
 ; CHECK:      subs	r0, r0, r1
-; CHECK-NEXT: movs	r1, #0
-; CHECK-NEXT: subs	r1, r1, r0
+; CHECK-NEXT: rsbs	r1, r0, #0
 ; CHECK-NEXT: adcs	r1, r0
 ; CHECK-NEXT: lsls	r0, r1, #2
 }