Fixed type naming for dynamically evaluated types (PY-8898).

python/src/com/jetbrains/python/psi/types/PyDynamicallyEvaluatedType.java

@@ -30,4 +30,10 @@ public class PyDynamicallyEvaluatedType extends PyUnionType {
     }
     return new PyDynamicallyEvaluatedType(members);
   }
+
+  @Override
+  public String getName() {
+    PyType res = excludeNull();
+    return res != null ? res.getName() : "unknown";
+  }
 }

python/src/com/jetbrains/python/psi/types/PyUnionType.java

@@ -163,8 +163,8 @@ public class PyUnionType implements PyType {
   /**
    * Excludes all subtypes of type from the union
    *
-   * @param type type to exclude. If type is a union all subtypes of union members will be excluded from the union
-   *             If type is null only null will be excluded from the union.
+   * @param type    type to exclude. If type is a union all subtypes of union members will be excluded from the union
+   *                If type is null only null will be excluded from the union.
    * @param context
    * @return union with excluded types
    */
@@ -186,6 +186,11 @@ public class PyUnionType implements PyType {
     return union(members);
   }
 
+  @Nullable
+  public PyType excludeNull() {
+    return exclude(null, null);
+  }
+
   private static PyType unit(@Nullable PyType type) {
     if (type instanceof PyUnionType) {
       Set<PyType> members = new LinkedHashSet<PyType>();