[BUG] pop.aligned_alloc can throw std::bad_alloc with no way to handle it

[owenhilyard]

Bug description

The mojo runtime does not provide an error handling mechanism for failed allocations. I expect to be able one of the following to happen:

1. The returned pointer is null.
2. memory.memory._malloc raises, meaning that all methods which can allocate also raise.

Steps to reproduce

Run the following program on system with less than 256 GB of memory (vm.overcommit_memory=0 or vm.overcommit_memory=2, vm.overcommit_memory=1 will produce a segfault while walking the array):

from memory import UnsafePointer, memset

fn main():
	alias len = 1024 * 1024 * 1024 * 256
	var foo = UnsafePointer[UInt8].alloc(len)
	if not foo:
		print("NULL")
	else:
		print("Not NULL")
		memset(foo, 1, len)
		var sum: UInt8 = 0
		for i in range(len):
			sum += foo[i]			
		print(sum)

If you use mojo run, you get LLVM ERROR: out of memory. If you use mojo build, you get:

terminate called after throwing an instance of 'std::bad_alloc'
  what():  std::bad_alloc
Aborted (core dumped)

Here's a C program that works as I expect:

#include <memory.h>
#include <stdio.h>
#include <limits.h>
#include <stdlib.h>

int main() {
        char* foo = malloc(((size_t)1024) * 1024 * 1024 * 256);
        if (foo == NULL) {
                printf("NULL\n");
        } else {
                printf("Not NULL\n");
        }
}

System information

OS: Ubuntu 22.04.5 LTS rootful podman container running on Ubuntu 24.04.1 LTS
CPU: AMD EPYC 7313P 16-Core
Memory: 128 GB