Fix size of bool handling in nimbase.h to unbreak build on powerpc-apple-darwin

[barracuda156]

Nim Version

2.2.6, master

Description

nimbase.h makes a non-portable assumption about size of bool, which breaks the build on powerpc-darwin.
https://github.com/nim-lang/csources_v3/blob/eeab3ac46e93f10efda8e58c4db02b9438319d71/c_code/nimbase.h#L328
Bool is not guaranteed to be 1-byte.

Current Output

error: static assertion failed

Expected Output

Known Workarounds

If size of bool does not matter, do not check for it, let compiler pick what is appropriate for a target.
If it must be 1-byte, do not use bool, use a type which is guaranteed to be 1-byte.

Additional Information

Size of bool in PowerPC 32-bit macOS ABI is 4 bytes.

[Araq]

The size of bool must be one byte.

[barracuda156]

The size of bool must be one byte.

Well, it does not have a fixed size. If nim_bool must be, then it should be a special type, like it is in rust.
C does not guarantee bool to be 1 byte.

[Araq]

Yes, I know. It must be mapped to (unsigned) char.

[barracuda156]

@Araq The current code refers to some issues, how to modify it correctly?

/* bool types (C++ has it): */
#ifdef __cplusplus
#define NIM_BOOL bool
#elif (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901)
// see #13798: to avoid conflicts for code emitting `#include <stdbool.h>`
#define NIM_BOOL _Bool
#else
typedef unsigned char NIM_BOOL; // best effort
#endif

Just use typedef unsigned char NIM_BOOL unconditionally?

Upd. I mean, unconditionally for ppc, not just for everything in bulk.