[turbofan] Turn Math.clz32 into an inlinable builtin.

src/compiler/arm/code-generator-arm.cc

Index: src/compiler/arm/code-generator-arm.cc
diff --git a/src/compiler/arm/code-generator-arm.cc b/src/compiler/arm/code-generator-arm.cc
index b9c3476128cd098df3927211c99d483d1e6a9d22..26ad5b03179d06c680e71f9e16ca521c33ab7c26 100644
--- a/src/compiler/arm/code-generator-arm.cc
+++ b/src/compiler/arm/code-generator-arm.cc
@@ -489,6 +489,10 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
                i.InputInt32(2));
       DCHECK_EQ(LeaveCC, i.OutputSBit());
       break;
+    case kArmClz:
+      __ clz(i.OutputRegister(), i.InputRegister(0));
+      DCHECK_EQ(LeaveCC, i.OutputSBit());
+      break;
     case kArmCmp:
       __ cmp(i.InputRegister(0), i.InputOperand2(1));
       DCHECK_EQ(SetCC, i.OutputSBit());