CREATE SCHEMA ... CREATE M.V. support

Hi!
I was exploring the PostgreSQL parser and discovered a very
interesting feature. Users can create schema along with schema objects
in single SQL.

So, for example
```
db1=# create schema shshshsh create table t1(i int) create view v1 as
select * from t1;
CREATE SCHEMA
```
works.

But `create schema shshshsh create materialized view v1 as select `
will not work.
I was trying to search for relevant discussions, but failed. It
appears that the feature has been available from 7.3 versions[1].
Support for materialized views began in 9.3. Perhaps, then, this is
simply something that was overlooked for support?

It appears that supporting this is as simple as changing this parser's
non-terminal [2]. However, perhaps there are justifications for why we
forbid this?

P.S. is this the correct place to make this question?

[1] https://git.postgresql.org/cgit/postgresql.git/tree/src/backend/parser/gram.y?h=REL7_3_STABLE#n802
[2] https://git.postgresql.org/cgit/postgresql.git/tree/src/backend/parser/gram.y?h=14e87ffa5c543b5f30ead7413084c25f7735039f#n1580
--
Best regards,
Kirill Reshke