quest(m4): plan benching TPDE and bumping the bench's moq pin

quest/m4/README.md

@@ -28,5 +28,7 @@ build's retired instructions by 16%.
 
 ## Required
 
+- [Bump the build benchmark's moq pin past poll-first](/quest/m4/bench-moq-pin.md) - the benchmark builds moq after poll-first, so its hub edit rebuilds the 10 crates main does
+- [Bench TPDE on moq](/quest/m4/tpde.md) - what TPDE cuts from moq's clean build and non-incremental edit; waits on `-Zllvm-tpde` reaching a nightly
 - [Waiting: a rustc and cargo fork](/quest/m4/fork.md) - the evidence ledger for carrying a fork; condition: enough measured reasons to pay for one
 - [moq in pure Go](/quest/m4/go/README.md) - rust2-go translating moq-net, with no cgo, fast enough to replace the cgo bindings for Go users

quest/m4/bench-moq-pin.md

@@ -0,0 +1,27 @@
+# [S] Bump the build benchmark's moq pin past poll-first
+
+## Goal
+
+The `moq` corpus in [corpus.toml](/bench/build/corpus.toml) pins a moq main
+after poll-first ([moq-dev/moq#7607](https://github.com/moq-dev/moq/pull/7607)),
+so the benchmark measures the moq its developers edit: the hub edit rebuilds the
+10 crates it rebuilds at main, not the pin's 8, and the async body edit is a
+thin wrapper over a `poll_*` function, as moq's rule makes it.
+
+## Plan
+
+Decided with the maintainer on 2026-11-07: m4. Found by the subset-compiler
+report ([moq-dev/rust2#615](https://github.com/moq-dev/rust2/pull/615)), which
+measured at moq main because the pin (`f36c848`) predates poll-first.
+
+- Land the bump on its own, as corpus.toml asks, so no report compares numbers
+  across it.
+- Update what names the old tree: the `sync` and `async` lines (at main,
+  `Session::closed` awaits `poll_closed`), the `test` package versions, and the
+  bench README's moq notes, such as the ra-jit bugs seen at the pin. At main,
+  the report saw `edit-async` fall back on usage-argv's `parsed_values_given`.
+- `moq-pure-crypto` is the old rev plus moq's `spike/pure-crypto` branch, so the
+  bump leaves it comparing a different tree. Recommended: merge moq main into a
+  new spike branch in moq-dev/moq and pin that, so the comparison still holds.
+- Out of scope: [nix.toml](/bench/build/nix.toml)'s own moq pin, which the Nix
+  comparison keeps for crane's dependency layer.

quest/m4/tpde.md

@@ -0,0 +1,40 @@
+# [M] Bench TPDE on moq
+
+## Goal
+
+The [build-speed benchmark](/bench/build/README.md) gains a `tpde` variant, on
+the nightly that ships `-Zllvm-tpde`, against `nightly` in the same job. Its
+report says how much TPDE, a fast O0 machine-code generator for LLVM IR, cuts
+moq's clean build and non-incremental hub edit, and how many codegen units fall
+back to LLVM.
+
+## Plan
+
+Decided with the maintainer on 2026-11-07: m4.
+
+What it targets, from the subset-compiler report
+([moq-dev/rust2#615](https://github.com/moq-dev/rust2/pull/615)) at moq main:
+LLVM is 21% of a clean build's rustc self-time and 28% of a non-incremental
+moq-net edit's (36% with building the IR, which TPDE does not replace), almost
+all of it O0 machine-code emission. The incremental edit spends 0.1% in LLVM,
+so expect nothing there. Cranelift, the existing lever on the same step, cut
+instructions by 16% clean and 25% on the non-incremental edit.
+
+- Bump the nightly in `flake.nix` to one that ships the flag, then add the
+  variant beside `cranelift` in [corpus.toml](/bench/build/corpus.toml), with
+  the same scenarios. `nightly` moves with the bump, so the variant's change
+  compares within one run.
+- Recommended: `-Zllvm-tpde=try`, which falls back to LLVM per module where
+  TPDE fails (inline and global assembly, SIMD, sanitizers); `=only` fails the
+  build instead. Report the fallback count.
+- Recommended: list it in the nightly moq job in
+  [bench.yml](/.github/workflows/bench.yml) beside `cranelift`, since upstream
+  plans to optimize the TPDE path after it lands.
+
+## Waiting
+
+- rust-lang/rust: [rust-lang/rust#164108](https://github.com/rust-lang/rust/pull/164108)
+  adds `-Zllvm-tpde`. Check that it merged and that a nightly from
+  `rust-bin.nightly` in `flake.nix` accepts the flag: `rustc -Z help` lists
+  `llvm-tpde`, and a `-Zllvm-tpde=only` build of a hello world succeeds, since
+  a shipped toolchain may build without TPDE.