A branch predicated on a constant can just FastEmit an unconditional branch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143086 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp
index a67c867..6aff834 100644
--- a/lib/Target/ARM/ARMFastISel.cpp
+++ b/lib/Target/ARM/ARMFastISel.cpp
@@ -1151,6 +1151,12 @@
       FuncInfo.MBB->addSuccessor(TBB);
       return true;
     }
+  } else if (const ConstantInt *CI =
+             dyn_cast<ConstantInt>(BI->getCondition())) {
+    uint64_t Imm = CI->getZExtValue();
+    MachineBasicBlock *Target = (Imm == 0) ? FBB : TBB;
+    FastEmitBranch(Target, DL);
+    return true;
   }
 
   unsigned CmpReg = getRegForValue(BI->getCondition());