Some objects declare their handle type as const, while others declare it
as constexpr. This makes the const ones constexpr for consistency, and
prevent unexpected compilation errors if these happen to be attempted to be
used within a constexpr context.
General moving to keep kernel object types separate from the direct
kernel code. Also essentially a preliminary cleanup before eliminating
global kernel state in the kernel code.
Implemented svcs GetResourceLimit, GetResourceLimitCurrentValues and GetResourceLimitLimitValues.
Note that the resource limits do not currently keep track of used objects, since we have no way to distinguish between an object created by the application, and an object created by some HLE module once we're inside Kernel::T::Create.
