Add IlProjection Typed depth via an importer per-instruction trace

[richlander]

What

Completes IlProjection's parity with the old AnnotatedILEmitter's three depths (#615 shipped Raw/Structured). The Typed depth annotates each instruction with the evaluation-stack types after it:

IL_0000: ldarg.0  // [string]
IL_0004: callvirt string::get_Length()  // [int]
IL_000A: ceq  // [bool]
IL_000C: ret  // []

How — one simulation, not two

The stack types come from the importer's own stack simulation, not a second pass. The importer optionally emits a per-instruction trace as a byproduct of the single import it already runs:

• An optional List<IlTracePoint>? trace threaded Build → BuildBlock.
• Recorded right after each opcode's switch arm, capturing the live Stack<IrExpression>'s ResultTypes. Prefix opcodes (constrained./volatile./…) continue past it and are correctly excluded; honest stops return before it.
• Null in the product import path, so IrImporter.Build is byte-identical there (trace?.Add is a no-op).

Project(…, Typed) runs the traced import for the types and reuses Decode for the instruction text + resolved operands — one decode, one simulation.

Parity note

The new view shows post-instruction stack state with the pipeline's richer typing (bool for ceq); the old emitter showed pre-instruction state and Int32. Same information, an improved spelling — consistent with the "exact-or-better" gate. The eventual annotated-IL consumer migration will diff against the old emitter and accept these as improvements.

Scope

Adds IlProjectionDepth.Typed and an internal IlTracePoint record. Still non-disruptive — no consumers migrated; IlProjection now has all three depths, completing the foundation before the consumer migration (MemberCodeProvider, harness DumpStages) and deletion of MethodBodyContext/MethodAnalysis/AnnotatedILEmitter.

Tests

+1 (Typed_AnnotatesPerInstructionStackTypes); ILInspector.Decompiler.Tests 441 pass. The product import path is unchanged (trace null), so no golden-output impact.

🤖 Generated with Claude Code