[arm] Fix test failures on old architectures.

src/compiler/arm/instruction-selector-arm.cc

Index: src/compiler/arm/instruction-selector-arm.cc
diff --git a/src/compiler/arm/instruction-selector-arm.cc b/src/compiler/arm/instruction-selector-arm.cc
index 1fdc12b9032862a0663f0930a3f5bfbe3e9beb10..f803d2641490baf288c2d3647652ee874ee90b87 100644
--- a/src/compiler/arm/instruction-selector-arm.cc
+++ b/src/compiler/arm/instruction-selector-arm.cc
@@ -326,7 +326,8 @@ void VisitMod(InstructionSelector* selector, Node* node, ArchOpcode div_opcode,
   } else {
     InstructionOperand mul_operand = g.TempRegister();
     selector->Emit(kArmMul, mul_operand, div_operand, right_operand);
-    selector->Emit(kArmSub, result_operand, left_operand, mul_operand);
+    selector->Emit(kArmSub | AddressingModeField::encode(kMode_Operand2_R),
+                   result_operand, left_operand, mul_operand);
   }
 }
 
@@ -1951,9 +1952,13 @@ void InstructionSelector::VisitAtomicStore(Node* node) {
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
-  MachineOperatorBuilder::Flags flags =
-      MachineOperatorBuilder::kInt32DivIsSafe |
-      MachineOperatorBuilder::kUint32DivIsSafe;
+  MachineOperatorBuilder::Flags flags;
+  if (CpuFeatures::IsSupported(SUDIV)) {
+    // The sdiv and udiv instructions correctly return 0 if the divisor is 0,
+    // but the fall-back implementation does not.
+    flags |= MachineOperatorBuilder::kInt32DivIsSafe |
+             MachineOperatorBuilder::kUint32DivIsSafe;
+  }
   if (CpuFeatures::IsSupported(ARMv7)) {
     flags |= MachineOperatorBuilder::kWord32ReverseBits;
   }