[builtins] Migrate a bunch of Math builtins to C++.

src/runtime/runtime-numbers.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 190 matching lines @@
     double value = HeapNumber::cast(obj)->value();
     int int_value = FastD2I(value);
     if (value == FastI2D(int_value) && Smi::IsValid(int_value)) {
       return Smi::FromInt(int_value);
     }
   }
   return isolate->heap()->nan_value();
 }
 
 
-RUNTIME_FUNCTION(Runtime_NumberImul) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 2);
-
-  // We rely on implementation-defined behavior below, but at least not on
-  // undefined behavior.
-  CONVERT_NUMBER_CHECKED(uint32_t, x, Int32, args[0]);
-  CONVERT_NUMBER_CHECKED(uint32_t, y, Int32, args[1]);
-  int32_t product = static_cast<int32_t>(x * y);
-  return *isolate->factory()->NewNumberFromInt(product);
-}
-
-
 // Compare two Smis as if they were converted to strings and then
 // compared lexicographically.
 RUNTIME_FUNCTION(Runtime_SmiLexicographicCompare) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 2);
   CONVERT_SMI_ARG_CHECKED(x_value, 0);
   CONVERT_SMI_ARG_CHECKED(y_value, 1);
 
   // If the integers are equal so are the string representations.
   if (x_value == y_value) return Smi::FromInt(EQUAL);
@@ skipping 94 matching lines @@
 
 RUNTIME_FUNCTION(Runtime_GetHoleNaNLower) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 0);
   return *isolate->factory()->NewNumberFromUint(kHoleNanLower32);
 }
 
 
 }  // namespace internal
 }  // namespace v8