__(U)INTPTR_WIDTH__ and __POINTER_WIDTH__ macros are too wide

[brooksdavis]

On 64-bit targets these are currently:

#define __INTPTR_WIDTH__ 128
#define __UINTPTR_WIDTH__ 128
#define __POINTER_WIDTH__ 128

C23 § 5.2.5.3.2 states:

For all signed integer types for which <limits.h> or <stdint.h> define a macro with suffix _WIDTH holding its width N , there are macros with suffix _MIN and _MAX holding the minimal and maximal values −2^(N−1) and 2^(N−1) − 1 that are representable by the type and that have the same type as would an expression that is an object of the corresponding type converted according to the integer promotions.

Which I think makes it clear that on 64-bit CHERI these should all be 64. (As further evidence of a lack of correspondence with sizeof, BOOL_WIDTH is defined to be exactly 1 at the top of the section).

[arichardson]

Good catch, I always assumed these were aliases for __foo_SIZE__ just in bits. It looks like we already have #define __BOOL_WIDTH__ 1 in clang trunk (but still #define __BOOL_WIDTH__ 8 in CHERI LLVM), so these should be 64 not 128.

Looking at https://godbolt.org/z/a8o7ed9oq it seems like this changed in clang 20.

[arichardson]

See llvm/llvm-project#117348