[turbofan] Add initial support for growing stores.

src/compiler/typer.cc

Index: src/compiler/typer.cc
diff --git a/src/compiler/typer.cc b/src/compiler/typer.cc
index 808e2c74356718b66ad015de1cc8a4be200136d0..ade80e7495197d5a47c072609d2ce2cd3241013d 100644
--- a/src/compiler/typer.cc
+++ b/src/compiler/typer.cc
@@ -726,6 +726,10 @@ Type* Typer::Visitor::TypeEnsureWritableFastElements(Node* node) {
   return Operand(node, 1);
 }
 
+Type* Typer::Visitor::TypeMaybeGrowFastElements(Node* node) {
+  return Operand(node, 1);
+}
+
 Type* Typer::Visitor::TypeTransitionElementsKind(Node* node) {
   UNREACHABLE();
   return nullptr;