[builtins] Migrate Math.log to TurboFan.

src/runtime/runtime-maths.cc

Index: src/runtime/runtime-maths.cc
diff --git a/src/runtime/runtime-maths.cc b/src/runtime/runtime-maths.cc
index 91b6181ab7aba5a6e0f10efce2b88f1cdebacb77..ee8c289fea7edf919ba0ff0126e394f18b632e0e 100644
--- a/src/runtime/runtime-maths.cc
+++ b/src/runtime/runtime-maths.cc
@@ -14,19 +14,6 @@
 namespace v8 {
 namespace internal {
 
-#define RUNTIME_UNARY_MATH(Name, name)                         \
-  RUNTIME_FUNCTION(Runtime_Math##Name) {                       \
-    HandleScope scope(isolate);                                \
-    DCHECK(args.length() == 1);                                \
-    isolate->counters()->math_##name##_runtime()->Increment(); \
-    CONVERT_DOUBLE_ARG_CHECKED(x, 0);                          \
-    return *isolate->factory()->NewHeapNumber(std::name(x));   \
-  }
-
-RUNTIME_UNARY_MATH(LogRT, log)
-#undef RUNTIME_UNARY_MATH
-
-
 RUNTIME_FUNCTION(Runtime_DoubleHi) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);