Add a MathFloor stub generated with TurboFan

src/compiler/typer.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/base/flags.h"
 #include "src/bootstrapper.h"
 #include "src/compiler/graph-reducer.h"
 #include "src/compiler/js-operator.h"
 #include "src/compiler/node.h"
 #include "src/compiler/node-properties.h"
@@ skipping 1561 matching lines @@
 Bounds Typer::Visitor::TypeJSCallFunction(Node* node) {
   return TypeUnaryOp(node, JSCallFunctionTyper);  // We ignore argument types.
 }
 
 
 Bounds Typer::Visitor::TypeJSCallRuntime(Node* node) {
   switch (CallRuntimeParametersOf(node->op()).id()) {
     case Runtime::kInlineIsSmi:
     case Runtime::kInlineIsNonNegativeSmi:
     case Runtime::kInlineIsArray:
+    case Runtime::kInlineIsMinusZero:
     case Runtime::kInlineIsFunction:
     case Runtime::kInlineIsRegExp:
       return Bounds(Type::None(zone()), Type::Boolean(zone()));
     case Runtime::kInlineDoubleLo:
     case Runtime::kInlineDoubleHi:
       return Bounds(Type::None(zone()), Type::Signed32());
     case Runtime::kInlineConstructDouble:
     case Runtime::kInlineMathFloor:
     case Runtime::kInlineMathSqrt:
     case Runtime::kInlineMathAcos:
@@ skipping 776 matching lines @@
       TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
     }
   }
   return Type::Constant(value, zone());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8