State every scalar type by its definition, never by the platform's

[estebanzimanyi]

A slot declared by a scalar typedef states what MEOS defines it as, read
from the typedef chain of the unit the catalog parses: the parser records
every typedef one step down, the C library's and libh3's included. A type
PostgreSQL declares in MobilityDB's vendored pgtypes keeps its name:
TimestampTz, DateADT, TimeADT, Oid, Datum. Any other integer typedef is
stated by the C standard type its chain reaches: int32 is int32_t, int16
is int16_t, H3Index, Quadbin and S2CellId are uint64_t. A chain meeting
neither ends at the C scalar it names, float8 at double. libclang's
resolution on the host is never the answer: it states TimeADT as long,
32 bits on Windows, and int32 as int.

A name defined as its own <stdint.h> name, as PostgreSQL 18's c.h
defines the historical names for types in <stdint.h> (typedef int32_t
int32), and a name for a C floating type (typedef double float8) name a
width and not a type of their own, so the chain goes on through them,
whichever header defines them. The other typedefs keep the spelling
_TYPE_MAP gives them (Jsonb, GSERIALIZED), and _TYPE_MAP still recovers a
name the preprocessor erased to int.

The service projection reads the C standard's integer types as integers,
as it reads int and long: a parameter or result spelled int64_t, uint64_t,
uint32_t, uint8_t or size_t is a JSON integer.

Why. Bindings key on canonical. A binding that read TimeADT as long read
32 bits on Windows, one that read uint64_t never met the int32 of the
same header spelled the same way, and every typedef missing from a hand
list reached the bindings as whatever libclang made of it on the host.
The chain leaves no list to complete: a new typedef is stated by its
definition.

Measured. Over MobilityDB 72abdf86c2, whose pg_basetypes.h defines int8
to uint64 as PostgreSQL 18's c.h does, 557 slots change:
258 int32, 111 int16 and 77 int32_t slots read int32_t and int16_t for
int and short, 35 uint8_t read uint8_t for unsigned char, 73 TimeADT read
TimeADT for long, and 3 Oid read Oid for unsigned int. 368 functions
taking or returning a C standard integer enter the service projection,
2516 exposable becoming 2860; 23 time functions and text_cmp leave it,
TimeADT and Oid joining the TimestampTz and DateADT the projection maps
to no wire type.

Witness. tests/test_typerecover.py follows the chains of a width name, a
cell, a PostgreSQL type, Datum over uintptr_t, a width name spelled as no
<stdint.h> type, a float and a name no scalar; reads PostgreSQL's names
from every scalar typedef of a pgtypes tree, whichever header declares
it, without its structs and pointers; and states a slot by its chain.
Over the catalog, no slot declared by a typedef reads as a C integer, and
TimeADT, DateADT, int32 and uint8_t slots read their definition.
tests/test_enrich.py reads int64_t, int32_t and uint32_t as JSON
integers. The suite floor goes from 343 to 354.