v0.20.0

Added

• Session-based per-file analysis API (AnalysisSession + FileAnalyzer) for incremental, file-scoped analysis suitable for LSP-style consumers.
• mir_analyzer::location_from_span(span, file, source, source_map) -> Location: public free function that converts a parser Span (byte-offset range) to the crate's Location type (1-based lines, 0-based codepoint columns), so consumers can translate Pass-2 spans to their own protocol's position format without re-implementing column math.
• Soft fallback for unknown stubs: when Pass 2 would emit UndefinedFunction / UndefinedClass for a name the build-time stub index recognises as a real PHP built-in, the diagnostic is suppressed. Defends against lazy-stub timing races (auto-discovery scanner false negatives, essentials-only sessions without auto-discovery, mid-ingest reads). Genuinely unknown names still emit.
• Concurrent-read benchmark: N reader threads call definition_of() in a tight loop while a writer continuously re-ingests a fixture, reporting wall time per fixed-size batch for 1 / 4 / 8 readers. Surfaces real contention characteristics under flat-out write pressure (per-read latency: 324ns @ 1 reader, 1.4µs @ 4, 1.9µs @ 8); realistic LSP edit cadence stays at the 324ns figure.
• MixedClone issue type: detects clone / clone with expressions on mixed-typed values in ExpressionAnalyzer.

Fixed

• @var annotation narrowing now applies to global-scope statements, not just function bodies. Previously analyze_stmt() (used for top-level statements) skipped the pre/post narrowing that analyze_stmts() performed for function bodies, so @var had no effect at global scope. Fixes global_with_var_no_indent, function_with_var, and invalid_mixed_clone fixtures.

Changed

• Analyzer boilerplate simplifications:
  • Union::core_type() collapses 10+ chained remove_null().remove_false() call sites in type-checking logic.
  • DefinitionCollector::parse_docblock_from_node_or_preceding() consolidates the "check doc_comment, fall back to preceding docblock" pattern repeated 11+ times across class/trait/interface collectors.
  • StatementsAnalyzer::span_to_location() replaces 7 instances of verbose span-to-location computation in flow analysis.