WebAssembly profile: bulk memory, reference types, and multi-value

Parent: #142 Depends on: #262 Roadmap: #134

Implement the mutually dependent post-MVP core baseline rather than accepting isolated opcodes incompletely.

Acceptance:

• Pin exact proposal/spec revisions and inventories for bulk memory, reference types, and multi-value.
• Decode, validate, instantiate, and execute all selected instructions/types/segments.
• Implement JavaScript API behavior and failure classes for the selected profile.
• Integrate table/reference edges with precise GC and cross-instance linking.
• Publish per-profile upstream command totals with zero hidden exclusions.

Child issue map

• #270 — multi-value functions and control flow
• #271 — reference and table types
• #272 — bulk memory and passive segments
• #273 — exact structural-profile conformance score

Implementation order

Multi-value (#270) and reference types (#271) may proceed independently. Bulk memory (#272) follows the reference table model, and the evidence issue (#273) closes only after all three implementation issues are complete.

Decomposed into #270-#273 so each runtime subsystem and the upstream evidence can close independently. Starting with #270; #271 can follow without waiting, while #272 deliberately depends on the finalized reference/table representation.

Reference types #271 is complete. The structural Core 2.0 baseline now has multi-value #270 and reference/table types #271 closed. Next implementation dependency is bulk memory/passive segments #272, followed by exact structural-profile evidence #273; this parent remains open until those gates close.

Bulk memory #272 is decomposed into #276 (binary/validator), #277 (memory/data lifecycle), and #278 (table/element/GC/API synchronization). Work starts with #276 so both runtime paths share one exact validated IR.

Bulk memory #272 and its children #276-#278 are complete. Multi-value #270, reference types #271, and bulk memory #272 now implement the structural runtime; #273 is the remaining child and must publish the exact pinned structural-profile command inventory before this parent closes.

Completed. All implementation children #270-#272 and exact evidence child #273 are closed. The pinned Core 2 structural inventory scores 27,437/27,437 applicable commands across all 90 official wg-2.0 core files, with 581 explicit text-format n/a commands and zero failures/runner errors; README/docs and bounded CI gates are published through 66a953a.