New rule: Identifiers should not shadow compiler intrinsics

### Prerequisites

- [X] This rule has not already been suggested.
- [X] This should be a new rule, not an improvement to an existing rule.
- [X] This rule would be generally useful, not specific to my code or setup.

### Suggested rule title

Identifiers should not shadow compiler intrinsics

### Rule description

This rule forbids identifiers that share a name with a compiler intrinsic.

This would include a configurable whitelist for acceptable intrinsics to shadow.

### Rationale

This can be confusing for a number of reasons:

- Compiler intrinsics have special "magic" behaviour that is not replaceable if it is shadowed (except by prefacing `System.`)
- Intrinsics are almost always expected to be the intrinsic value (e.g. `Break`, `Continue`, `True`)
- The Delphi IDE adds decorators for certain intrinsics, and does not differentiate between the intrinsic and a shadowing identifier of the same name