[builtins] Introduce proper Float64Tan operator.

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 fb8e083debff2cca7f0ad648aa9d49d5dadfdb72..1a923bfa68f62b774fd800300698fdc3f7b31b1f 100644
--- a/src/runtime/runtime-maths.cc
+++ b/src/runtime/runtime-maths.cc
@@ -9,7 +9,6 @@
 #include "src/base/utils/random-number-generator.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
-#include "src/third_party/fdlibm/fdlibm.h"
 
 namespace v8 {
 namespace internal {
@@ -36,29 +35,6 @@ RUNTIME_FUNCTION(Runtime_DoubleLo) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_ConstructDouble) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 2);
-  CONVERT_NUMBER_CHECKED(uint32_t, hi, Uint32, args[0]);
-  CONVERT_NUMBER_CHECKED(uint32_t, lo, Uint32, args[1]);
-  uint64_t result = (static_cast<uint64_t>(hi) << 32) | lo;
-  return *isolate->factory()->NewNumber(uint64_to_double(result));
-}
-
-
-RUNTIME_FUNCTION(Runtime_RemPiO2) {
-  SealHandleScope shs(isolate);
-  DisallowHeapAllocation no_gc;
-  DCHECK(args.length() == 2);
-  CONVERT_DOUBLE_ARG_CHECKED(x, 0);
-  CONVERT_ARG_CHECKED(JSTypedArray, result, 1);
-  CHECK(result->byte_length() == Smi::FromInt(2 * sizeof(double)));
-  FixedFloat64Array* array = FixedFloat64Array::cast(result->elements());
-  double* y = static_cast<double*>(array->DataPtr());
-  return Smi::FromInt(fdlibm::rempio2(x, y));
-}
-
-
 // Slow version of Math.pow.  We check for fast paths for special cases.
 // Used if VFP3 is not available.
 RUNTIME_FUNCTION(Runtime_MathPow) {