[compiler] Generalize JSContextSpecialization.

src/compiler/node-properties.cc

Index: src/compiler/node-properties.cc
diff --git a/src/compiler/node-properties.cc b/src/compiler/node-properties.cc
index 78a64593ba6b04422e94c1b47818013af6c884f9..cc3a07d7e3616867d44729ad9d97aa96e48c0484 100644
--- a/src/compiler/node-properties.cc
+++ b/src/compiler/node-properties.cc
@@ -339,6 +339,17 @@ MaybeHandle<Context> NodeProperties::GetSpecializationContext(
 
 
 // static
+Node* NodeProperties::GetOuterContext(Node* node, size_t* depth) {
+  Node* context = NodeProperties::GetContextInput(node);
+  while (*depth > 0 &&
+         IrOpcode::IsContextChainExtendingOpcode(context->opcode())) {
+    context = NodeProperties::GetContextInput(context);
+    (*depth)--;
+  }
+  return context;
+}
+
+// static
 Type* NodeProperties::GetTypeOrAny(Node* node) {
   return IsTyped(node) ? node->type() : Type::Any();
 }