[builtins] Migrate Math.log to TurboFan.

src/compiler/machine-operator-reducer.cc

Index: src/compiler/machine-operator-reducer.cc
diff --git a/src/compiler/machine-operator-reducer.cc b/src/compiler/machine-operator-reducer.cc
index 4b50ffe61ea46c67bd5ae376de040c4123ec9eb3..1853da2191835db69355b6a9ea6599d78c88d5f6 100644
--- a/src/compiler/machine-operator-reducer.cc
+++ b/src/compiler/machine-operator-reducer.cc
@@ -382,6 +382,11 @@ Reduction MachineOperatorReducer::Reduce(Node* node) {
       }
       break;
     }
+    case IrOpcode::kFloat64Log: {
+      Float64Matcher m(node->InputAt(0));
+      if (m.HasValue()) return ReplaceFloat64(std::log(m.Value()));
+      break;
+    }
     case IrOpcode::kChangeFloat32ToFloat64: {
       Float32Matcher m(node->InputAt(0));
       if (m.HasValue()) return ReplaceFloat64(m.Value());