Add NOB_ASSERT that doesnt depend on assert.h

[screaminglineage]

The main issue this solves is that when the assert() from libc is called in a debugger, you end up several stack levels deep and have to hunt down where the crash actually occurred.

It ends up looking like this.

This approach instead makes the compiler generate a trap instruction and crash immediately.

PS: You could also implement cool custom formatting for asserts, but I didn't put that in for the sake of keeping it simple.

#define assertf(expr, ...)    \
    (!(expr))?     \
        (printf("%s:%d: assertion `%s` failed: \"", __FILE__, __LINE__, #expr),    \
        printf(__VA_ARGS__),  \
        printf('\"\n'),  \ 
        CRASH())    \ 
    : (void)0

assertf(a == b, "expected %d but got %d", a, b);