Add support for atomic_max* and atomic_umax* intinsics

[adpaco-aws]

Description of changes:

Same deal as #1212, but this time for intrinsics using a max comparison.

Resolved issues:

Part of #1163

Call-outs:

#25 will be tackled in batch mode, after all atomic intrinsics are in.

Testing:

• How is this change tested? Removes 10 negative tests, adds 2.

• Is this a refactor change? No.

Checklist

• Each commit message has a non-empty body, explaining why the change was made
• Methods or procedures are documented
• Regression or unit tests are included, or existing tests cover the modified code
• My PR is restricted to a single feature or bugfix

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 and MIT licenses.

[tedinski]

I like the test consolidation