[turbofan] Use InternalizedString feedback abstract/strict equality comparisons.

src/compiler/typer.cc

Index: src/compiler/typer.cc
diff --git a/src/compiler/typer.cc b/src/compiler/typer.cc
index 560e3a4cbf7cf20d25910199d25a2c2de5711844..51b8352b3126a012290ec3298e85162ced0bd3ec 100644
--- a/src/compiler/typer.cc
+++ b/src/compiler/typer.cc
@@ -1716,6 +1716,11 @@ Type* Typer::Visitor::TypeCheckIf(Node* node) {
   return nullptr;
 }
 
+Type* Typer::Visitor::TypeCheckInternalizedString(Node* node) {
+  Type* arg = Operand(node, 0);
+  return Type::Intersect(arg, Type::InternalizedString(), zone());
+}
+
 Type* Typer::Visitor::TypeCheckMaps(Node* node) {
   UNREACHABLE();
   return nullptr;