[builtins] implement Array.prototype.includes in TurboFan

src/compiler/typer.cc

Index: src/compiler/typer.cc
diff --git a/src/compiler/typer.cc b/src/compiler/typer.cc
index 04e0b5af62e5271624e52d06cbd238b9277d57f1..47b5fe412c93bfc488767898860d9520f25576c0 100644
--- a/src/compiler/typer.cc
+++ b/src/compiler/typer.cc
@@ -827,6 +827,25 @@ Type* Typer::Visitor::JSStrictEqualTyper(Type* lhs, Type* rhs, Typer* t) {
   return Type::Boolean();
 }
 
+Type* Typer::Visitor::JSSameValueZeroTyper(Type* lhs, Type* rhs, Typer* t) {
+  if (!JSType(lhs)->Maybe(JSType(rhs))) return t->singleton_false_;
+  if (lhs->Is(Type::NaN()) || rhs->Is(Type::NaN())) return t->singleton_true_;
+  if (lhs->Is(Type::Number()) && rhs->Is(Type::Number()) &&
+      (lhs->Max() < rhs->Min() || lhs->Min() > rhs->Max())) {
+    return t->singleton_false_;
+  }
+  if ((lhs->Is(t->singleton_the_hole_) || rhs->Is(t->singleton_the_hole_)) &&
+      !lhs->Maybe(rhs)) {
+    return t->singleton_false_;
+  }
+  if (lhs->IsConstant() && rhs->Is(lhs)) {
+    // Types are equal and are inhabited only by a single semantic value,
+    // which is not nan due to the earlier check.
+    return t->singleton_true_;
+  }
+  return Type::Boolean();
+}
+
 
 Type* Typer::Visitor::JSStrictNotEqualTyper(Type* lhs, Type* rhs, Typer* t) {
   return Invert(JSStrictEqualTyper(lhs, rhs, t), t);