[proggeramlug]

Summary

Fixes #1698. Request's body methods (json/text/arrayBuffer) worked as a direct typed call (req.json(), #1688) but failed when accessed as a value or via a computed key:

const req = new Request('http://x/y', { method:'POST', headers:{'content-type':'application/json'}, body:'{"x":1}' });
typeof req.json            // 'object'    → now 'function'
typeof (req as any)[key]   // 'undefined' → now 'function'
await (req as any)[key]()  // null        → now { x: 1 }

The value-read / computed-key / as any forms lose the static Request type at codegen, so they land in the runtime's generic dynamic-dispatch tower (js_native_call_method → small-handle range → js_handle_method_dispatch / js_handle_property_dispatch), which had no Request body-method arm. This blocks Hono's c.req.json() end-to-end (#1655): HonoRequest.#cachedBody does raw[key]() — a computed-key call on the underlying Request.

Approach (runtime, type-agnostic)

Per the issue discussion, this is the unified handle-id + runtime probe approach. Because the dispatch happens at runtime, it covers every form — typed req[key](), (req as any).json(), and Hono's untyped raw[key]() — not just the statically-typed case.

• dispatch_request_method (text/json/arrayBuffer) wired into js_handle_method_dispatch, mirroring the existing dispatch_response_method.
• dispatch_request_property returns js_class_method_bind bound-method values for json/text/arrayBuffer, so typeof req[key] === 'function' and the value stays callable (the Web Streams: inline stream-handle property read segfaults + for-await over res.body (follow-up to #1650) #1670 stream-property pattern).
• Unified fetch-family handle id counter (NEXT_FETCH_HANDLE_ID) across Request/Response/Headers/Blob. Previously each had its own counter starting at 1, so a Request id could equal a Response id and the registry-membership dispatch gate was ambiguous. One counter ⇒ an id belongs to exactly one registry ⇒ unambiguous dispatch (this also makes new Response(body)[key]() and Response computed-key / typeof work).
• typeof req.json codegen fold for the LITERAL value-read (it takes the typed Web-Fetch path that bypasses the property dispatch). Covers Request + Response.

Verification

All match node --experimental-strip-types byte-for-byte:

• The issue repro (typeof literal, typeof computed, computed-key call).
• typed / computed / as any × value-read / call variants, plus text.
• Hono POST /api/echo doing await c.req.json() → status=200, body={"body":{"x":1}}.
• test_gap_fetch_response.ts (Response / Headers / Request / Blob / redirect) — identical, no regression.
• perry-hir + perry-stdlib unit tests pass; cargo fmt --all -- --check clean.

Out of scope (separate, pre-existing)

By-default Hono compilation still hits a separate guard: #503 refuses hono's internal path[runtimeVar]() dynamic dispatch (in perry-hir/src/lockdown.rs — untouched by this PR). With that guard bypassed, the Hono path above works end-to-end. The path[...] guard is tracked separately under the #1655 umbrella.

Test

test-files/test_issue_1698_request_body_method_value.ts

[proggeramlug]

Follow-up filed: #1701 — the default Hono compile is blocked by a separate pre-existing guard (#503 false-positives on hono's local variable named path), not by anything in this PR. With that guard bypassed, the Hono c.req.json() path verified end-to-end.