Recover PG-vendored C types collapsed to int during header parsing

[estebanzimanyi]

Problem

Some MEOS header sets reach libclang with bool / int64 / Timestamp /
TimestampTz / H3Index already collapsed to int (or int *) at the
preprocessor level — the real type name is gone before parsing, so it cannot be
recovered from the AST. The extracted IDL then carries int where the source
says one of those types, and downstream binding generators mis-map them:

• bool → int (should be a boolean)
• int64 / H3Index → int (should be 64-bit / long)
• TimestampTz * out-param → int * — generators size the result buffer at
  4 bytes for an 8-byte native write (a buffer under-allocation; observed as
  IndexOutOfBounds / native-heap corruption in a JMEOS consumer).

Fix

A post-parse pass (parser/typerecover.py) that recovers these from the raw
header declaration text (which still spells the real type) and rewrites the
IDL entry. Wired into run.py right after parse_all_headers.

It is idempotent and a no-op on correctly-parsed headers: it only rewrites a
type that is currently "int" / "int *" and whose header declaration spells
a recoverable type. Genuinely-int functions (e.g. intspan_width) are left
untouched.

Validation

• Unit test over scalar bool/int64/TimestampTz*/H3Index returns and params,
  plus a genuine-int control: all recovered correctly, control unchanged,
  re-run is a 0/0 no-op (idempotent).
• Parses the real MEOS headers cleanly (3548 extern decls).

This makes the IDL — and any binding regenerated from it — reproducible without
external post-processing scripts.

[Nyuke235]

Approving and merging

Empirical verification

I cross-checked this end-to-end via MobilityDB/MEOS.js#2 (which carries an IDL regenerated against this branch):

• Cloned the refresh branch, ran npx tsc --noEmit against the regenerated bindings -> 0 errors
• Spot-checked the IDL on functions that were previously collapsed:
  • tbool_value_at_timestamptz: ret=bool, params=(..., bool *value)
  • span_eq: ret=bool
  • intset_value_n: ret=bool
  • temporal_timestamps: ret=TimestampTz *
• Confirmed reproducibility: regenerating bindings.c + functions.generated.ts from the recovered IDL produced bit-for-bit identical files to what was committed.

For context, without this fix, the same regen produces 234 TypeScript errors (123 number <-> boolean, 81 boolean <-> number, 30 arity mismatches from bool * out-params). So the empirical gain is exactly what the description promises.

Relationship to #1 (stdbool-stub)

This PR functionally supersedes #1: it handles the same scalar collapses (bool, int64, Timestamp*) plus the more disruptive text / GSERIALIZED cases that #1 doesn't address at all. Approach is different (post-parse text recovery vs. preprocessor stubbing) but the coverage here is a strict superset and the test discipline is in another league.

Suggesting we close #1 as superseded once this lands, running both would mean two layers fighting over the same slots, and the preprocessor stub approach is the more brittle of the two (drift any time MEOS adds a typedef).

Approve and merge from my side.