The block to inspect.
Resolved per-rule severities. Defaults to RULE_DEFAULTS.
Optionalindex: SuppressionIndexSuppression index to consult. Callers that already built one
(blockToDiagnostics) pass it in so directives are parsed once; direct
callers get one built here.
Any SemanticWarnings found (empty when none apply).
Run every semantic rule over a parsed Block and return all findings. Each rule decides its own applicability (by diagram type), reads its severity from
rules(skipping whenoff), and honors suppression directives via the supplied (or freshly built) SuppressionIndex.