Revert of [builtins] Introduce proper Float64Exp operator.

src/arm/codegen-arm.h

Index: src/arm/codegen-arm.h
diff --git a/src/arm/codegen-arm.h b/src/arm/codegen-arm.h
index 00867392ed2758c57ce40742dd11bdebe38144a1..880825a1be0e4fc21df3117064cedf3964754c98 100644
--- a/src/arm/codegen-arm.h
+++ b/src/arm/codegen-arm.h
@@ -28,6 +28,22 @@
 };
 
 
+class MathExpGenerator : public AllStatic {
+ public:
+  // Register input isn't modified. All other registers are clobbered.
+  static void EmitMathExp(MacroAssembler* masm,
+                          DwVfpRegister input,
+                          DwVfpRegister result,
+                          DwVfpRegister double_scratch1,
+                          DwVfpRegister double_scratch2,
+                          Register temp1,
+                          Register temp2,
+                          Register temp3);
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MathExpGenerator);
+};
+
 }  // namespace internal
 }  // namespace v8