X87: Make fast_exp take an Isolate* paramter.

src/x87/codegen-x87.cc

Index: src/x87/codegen-x87.cc
diff --git a/src/x87/codegen-x87.cc b/src/x87/codegen-x87.cc
index 46abc1cfb0b4e9d411b25646d5a1d317363b1ed3..f4751d821d74af032a996aa748d1176c5457cdd9 100644
--- a/src/x87/codegen-x87.cc
+++ b/src/x87/codegen-x87.cc
@@ -32,11 +32,10 @@ void StubRuntimeCallHelper::AfterCall(MacroAssembler* masm) const {
 
 
 #define __ masm.
+double x87_std_exp(double x, Isolate* isolate) { return std::exp(x); }
 
-
-UnaryMathFunction CreateExpFunction() {
-  // No SSE2 support
-  return nullptr;
+UnaryMathFunctionWithIsolate CreateExpFunction(Isolate* isolate) {
+  return x87_std_exp;

[jochen (gone - plz use gerrit), 2015/11/25 09:01:37]

the init_fast_exp_function() in codegen.cc already uses std::exp with
CreateExpFunction returns a nullptr

 }