PPC/s390: [builtins] Introduce proper Float64Exp operator.

src/s390/codegen-s390.h

Index: src/s390/codegen-s390.h
diff --git a/src/s390/codegen-s390.h b/src/s390/codegen-s390.h
index 18cf8e29d1eca35080541112a33277445eddfd97..aaedb01751edfff4f5d6194645a529e302029712 100644
--- a/src/s390/codegen-s390.h
+++ b/src/s390/codegen-s390.h
@@ -25,19 +25,6 @@ class StringCharLoadGenerator : public AllStatic {
  private:
   DISALLOW_COPY_AND_ASSIGN(StringCharLoadGenerator);
 };
-
-class MathExpGenerator : public AllStatic {
- public:
-  // Register input isn't modified. All other registers are clobbered.
-  static void EmitMathExp(MacroAssembler* masm, DoubleRegister input,
-                          DoubleRegister result, DoubleRegister double_scratch1,
-                          DoubleRegister double_scratch2, Register temp1,
-                          Register temp2, Register temp3);
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(MathExpGenerator);
-};
-
 }  // namespace internal
 }  // namespace v8