Logical negation of class handles

In core-v-verif there are 51 violations of the linter's "Logical Violation" rule. You are in the "assignees" list of this issue because git believes you authored one or more of these.

The Verissimo linter flags these as a NON_STANDARD violation. The specific violation in question is using logical negation on operands of class handles. The linter suggests using == null instead.

Possible resolutions:

1. Accept the use of if (!obj) and create a project-wide waiver for the NON_STANDARD rule.
2. Convert all instances of if (!obj) to if (obj == null).
3. Waive, or not, on a case-by-case basis.

Steps to Reproduce

Lint checks are run every six hours - the link above will show all violations of this rule.

Additional context

This is a set of linter issues identified by the Verissimo SystemVerilog Testbench Linter. Please reach out to me directly if you have questions about the tool.