Revert "[promises] Add an optimizer for Seq, TrySeq (grpc#38445)" (…

…grpc#38748)

This reverts commit a7a650a.

Original PR breaks grpc#38286 and I think the breakage is in the PR -- in a construct like:

```
TrySeq(
  /*a*/ []() -> Promise<absl::Status>,
  /*b*/ []() -> Promise<StatusFlag>,
  /*c*/ []() -> Promise<absl::Status>)
```

the original seq_state code would try to promote the intermediate `StatusFlag` to an `absl::Status` which is great - however with the optimization, if `b` is instantaneous we try to demote the result of `a` to `StatusFlag`, losing information.

I'll need to consider how to change this optimization to preserve the final output type before rolling forward.

Closes grpc#38748

COPYBARA_INTEGRATE_REVIEW=grpc#38748 from ctiller:rb1 743eb33
PiperOrigin-RevId: 727109120

src/core/BUILD

@@ -1012,14 +1012,12 @@ grpc_cc_library(
     ],
     deps = [
         "construct_destruct",
-        "map",
         "poll",
         "promise_factory",
         "promise_like",
         "//:debug_location",
         "//:gpr",
         "//:grpc_trace",
-        "//:promise",
     ],
 )
 

src/core/lib/promise/detail/promise_factory.h

@@ -184,7 +184,6 @@ class OncePromiseFactory {
   using Arg = A;
   using Promise =
       decltype(PromiseFactoryImpl(std::move(f_), std::declval<A>()));
-  static constexpr bool kInstantaneousPromise = Promise::kInstantaneous;
 
   GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION explicit OncePromiseFactory(F f)
       : f_(std::move(f)) {}
@@ -194,14 +193,6 @@ class OncePromiseFactory {
   }
 };
 
-template <typename A, typename F>
-GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION
-    std::enable_if_t<OncePromiseFactory<A, F>::kInstantaneousPromise,
-                     typename OncePromiseFactory<A, F>::Promise::Result>
-    MakeAndCall(A&& a, OncePromiseFactory<A, F>& f) {
-  return f.Make(std::forward<A>(a)).CallUnderlyingFn();
-}
-
 template <typename F>
 class OncePromiseFactory<void, F> {
  private:
@@ -210,7 +201,6 @@ class OncePromiseFactory<void, F> {
  public:
   using Arg = void;
   using Promise = decltype(PromiseFactoryImpl(std::move(f_)));
-  static constexpr bool kInstantaneousPromise = Promise::kInstantaneous;
 
   GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION explicit OncePromiseFactory(F f)
       : f_(std::move(f)) {}
@@ -220,14 +210,6 @@ class OncePromiseFactory<void, F> {
   }
 };
 
-template <typename F>
-GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION
-    std::enable_if_t<OncePromiseFactory<void, F>::kInstantaneousPromise,
-                     typename OncePromiseFactory<void, F>::Promise::Result>
-    MakeAndCall(OncePromiseFactory<void, F>& f) {
-  return f.Make().CallUnderlyingFn();
-}
-
 template <typename A, typename F>
 class RepeatedPromiseFactory {
  private:

src/core/lib/promise/detail/promise_like.h

@@ -53,15 +53,13 @@ struct PollWrapper {
   GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION static Poll<T> Wrap(T&& x) {
     return Poll<T>(std::forward<T>(x));
   }
-  static constexpr bool kInstantaneous = true;
 };
 
 template <typename T>
 struct PollWrapper<Poll<T>> {
   GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION static Poll<T> Wrap(Poll<T>&& x) {
     return std::forward<Poll<T>>(x);
   }
-  static constexpr bool kInstantaneous = false;
 };
 
 template <typename T>
@@ -89,15 +87,12 @@ class PromiseLike<
   using WrappedResult = decltype(WrapInPoll(std::declval<OriginalResult>()));
 
  public:
-  static constexpr bool kInstantaneous =
-      PollWrapper<std::invoke_result_t<F>>::kInstantaneous;
   // NOLINTNEXTLINE - internal detail that drastically simplifies calling code.
   GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION PromiseLike(F&& f)
       : f_(std::forward<F>(f)) {}
   GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION WrappedResult operator()() {
     return WrapInPoll(f_());
   }
-  GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION auto CallUnderlyingFn() { return f_(); }
   PromiseLike(const PromiseLike&) = default;
   PromiseLike& operator=(const PromiseLike&) = default;
   PromiseLike(PromiseLike&&) = default;
@@ -112,18 +107,13 @@ class PromiseLike<
   GPR_NO_UNIQUE_ADDRESS RemoveCVRef<F> f_;
 
  public:
-  static constexpr bool kInstantaneous = true;
   // NOLINTNEXTLINE - internal detail that drastically simplifies calling code.
   GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION PromiseLike(F&& f)
       : f_(std::forward<F>(f)) {}
   GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION Poll<Empty> operator()() {
     f_();
     return Empty{};
   }
-  GPR_ATTRIBUTE_ALWAYS_INLINE_FUNCTION auto CallUnderlyingFn() {
-    f_();
-    return Empty{};
-  }
   PromiseLike(const PromiseLike&) = default;
   PromiseLike& operator=(const PromiseLike&) = default;
   PromiseLike(PromiseLike&&) = default;