Use `==` instead of `instanceof` for primitive array type checks

[sbrannen]

Overview

For performance reasons, JDK libraries often use == instead of instanceof for primitive array type checks — for example, if (obj.getClass() == char[].class) instead of if (obj instanceof char[]).

The rationale is that there are no type hierarchies for primitive array types. Consequently using instanceof is unnecessary.

We should therefore migrate from instanceof to == where feasible.

Candidates

• SynthesizedMergedAnnotationInvocationHandler.cloneArray(Object)
• ObjectUtils.arrayEquals(Object, Object)