Change shell interpreter to bash

[rokclimb15]

Description

This file uses some purely bash syntax like function and will not execute correctly on a system with a different interpreter aliased to /bin/sh

Motivation and Context

Systems like Ubuntu don't have /bin/bash aliased to /bin/sh

Testing

./build64.sh now executes without error

Types of changes

• Bug fix (non-breaking change which fixes an issue)

License

• By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.