Fixed issues 2299, 2301, and 2307

[Hydrocharged]

This fixes:

• Panic: nil pointer dereference when using DEFAULT on ENUM column #2299
• SELECT EXISTS(...) returns INT2 instead of BOOL, breaking typed PostgreSQL clients #2307

For 2299, we were only resolving the column type, and not the types within default values, so we ended up with an unresolved type that was persisted in the schema. Since we assume that every deserialized type is resolved, this would cause a panic when fields were missing.

For 2307, we return the schema from the unanalyzed node obtained right after parsing the node. Our analysis passes handle type conversions between GMS types (with EXISTS being a node defined in GMS), and therefore we were returning a GMS type (which was being automatically converted to the wrong type). We now attempt an analysis pass before determining the schema, which should work in most cases, but may fail for some bindings. In those cases, we ignore the analysis error and return the original schema. This isn't a complete solution, but it at least gets us further in all other cases.

This most likely fixes:

• Panic when executing large CREATE TABLE migration via extended query protocol (SQLx) #2301

2301 seems related to 2299. We don't appear to have any intrinsic problem with many CREATE TABLE statements within Rust's sqlx library (as used in the issue filed, 30 statements work fine), so it appears tied to the other issue. It's possible that there are further issues masked by the aforementioned one, but that cannot be determined without the user's migration data.

[github-actions]

	Main	PR
covering_index_scan_postgres	549.55/s	554.89/s	+0.9%
index_join_postgres	122.63/s	120.89/s	-1.5%
index_join_scan_postgres	176.42/s	176.19/s	-0.2%
index_scan_postgres	11.22/s	11.13/s	-0.9%
oltp_point_select	2359.64/s	2367.95/s	+0.3%
oltp_read_only	1691.15/s	1698.73/s	+0.4%
select_random_points	108.50/s	106.32/s	-2.1%
select_random_ranges	428.26/s	416.37/s	-2.8%
table_scan_postgres	11.07/s	10.97/s	-1.0%
types_table_scan_postgres	5.03/s	5.04/s	+0.1%

[github-actions]

	Main	PR
Total	42090	42090
Successful	17559	17559
Failures	24531	24531
Partial Successes1	5585	5585

	Main	PR
Successful	41.7177%	41.7177%
Failures	58.2823%	58.2823%

Footnotes

1. These are tests that we're marking as Successful, however they do not match the expected output in some way. This is due to small differences, such as different wording on the error messages, or the column names being incorrect while the data itself is correct. ↩

[zachmu]

LGTM, just a comment about tests