extends the char buffer in the strsignal function to cover the
entire range of `int`
Had to use `-INT_MAX` as the compiler resolves
```
STRINGIFY(INT_MIN)
```
to:
```
(-2147483647 - 1)
```
instead of:
```
-2147483648
```
Signed-off-by: Yong Cong Sin <ycsin@meta.com>
43123e77c0