Exit Code has wrong value when unreachable is reached

[ptitSeb]

Describe the bug

According to wasi.fyi libc test suite, when unreachable is reached, like when compiling an abort() function with WASI, the error code return should be 132. Wasmer return 1.

The C program is here

#include <stdlib.h>

int main(void) {
    abort();

    return 0;
}

wich gives the attached wasm file. But basically, it's just an unreachable reached.
abort.zip

Same issue with the "assert-false" test:

#include <assert.h>
#include <stdbool.h>

int main(void) {
    assert(false);

    return 0;
}

[syrusakbary]

This was fixed with #3266