fix #23817; Use __builtin_saddl_overflow variants for arm-none-eabi-gcc. (#23835)

Provides a fix for #23817. 

With target `arm-none-eabi`, GCC defines `int32_t` to `long int`. Nim
uses `__builtin_sadd_overflow` for 32-bit targets, but this emits
warnings on GCC releases 13 and under, while generating an error on GCC
14. More info regarding this
[here](https://gcc.gnu.org/gcc-14/porting_to.html#c) and
[here](https://gcc.gnu.org/pipermail/gcc-cvs/2023-December/394351.html).

The proposed PR attempts to address this issue for these targets by
defining the `nimAddInt`, `nimSubInt`, and `nimMulInt` macros to use the
appropriate compiler intrinsics for this platform.

As for as we know, the LLVM toolchain for bare metal Arm does not define
`int32_t` as `long int` and has no need for this patch. Thus, we only
define the above macros for GCC targeting `arm-non-eabi`.

0 files changed, 0 insertions, 0 deletions