[api][fastcall] Small TryCopyAndConvertArrayToCppBuffer fixes

- Add V8_WARN_UNUSED_RESULT to TryCopyAndConvertArrayToCppBuffer
  methods
- Remove --force-slow-path implications in
  Object::IterationHasObservableEffects

Bug: v8:11739
Change-Id: I20dcac1c460c6ee116ff372806cdf8764a99d9f1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3063504
Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76037}

include/v8-fast-api-calls.h

@@ -788,17 +788,19 @@ static constexpr CTypeInfo kTypeInfoFloat64 =
  * returns true on success. `type_info` will be used for conversions.
  */
 template <const CTypeInfo* type_info, typename T>
-bool V8_EXPORT TryCopyAndConvertArrayToCppBuffer(Local<Array> src, T* dst,
-                                                 uint32_t max_length);
+bool V8_EXPORT V8_WARN_UNUSED_RESULT TryCopyAndConvertArrayToCppBuffer(
+    Local<Array> src, T* dst, uint32_t max_length);
 
 template <>
-inline bool TryCopyAndConvertArrayToCppBuffer<&kTypeInfoInt32, int32_t>(
+inline bool V8_WARN_UNUSED_RESULT
+TryCopyAndConvertArrayToCppBuffer<&kTypeInfoInt32, int32_t>(
     Local<Array> src, int32_t* dst, uint32_t max_length) {
   return CopyAndConvertArrayToCppBufferInt32(src, dst, max_length);
 }
 
 template <>
-inline bool TryCopyAndConvertArrayToCppBuffer<&kTypeInfoFloat64, double>(
+inline bool V8_WARN_UNUSED_RESULT
+TryCopyAndConvertArrayToCppBuffer<&kTypeInfoFloat64, double>(
     Local<Array> src, double* dst, uint32_t max_length) {
   return CopyAndConvertArrayToCppBufferFloat64(src, dst, max_length);
 }

src/objects/objects.cc

@@ -1762,10 +1762,6 @@ bool Object::IterationHasObservableEffects() {
   JSArray array = JSArray::cast(*this);
   Isolate* isolate = array.GetIsolate();
 
-#ifdef V8_ENABLE_FORCE_SLOW_PATH
-  if (isolate->force_slow_path()) return true;
-#endif
-
   // Check that we have the original ArrayPrototype.
   i::HandleScope handle_scope(isolate);
   i::Handle<i::Context> context;

test/mjsunit/compiler/fast-api-sequences-x64.js

@@ -11,9 +11,6 @@
 // The test relies on optimizing/deoptimizing at predictable moments, so
 // it's not suitable for deoptimization fuzzing.
 // Flags: --deopt-every-n-times=0
-// The test relies on TryCopyAndConvertArrayToCppBuffer that fails with
-// --force-slow-path.
-// Flags: --no-force-slow-path
 
 d8.file.execute('test/mjsunit/compiler/fast-api-helpers.js');
 

test/mjsunit/compiler/fast-api-sequences.js

@@ -11,9 +11,6 @@
 // The test relies on optimizing/deoptimizing at predictable moments, so
 // it's not suitable for deoptimization fuzzing.
 // Flags: --deopt-every-n-times=0
-// The test relies on TryCopyAndConvertArrayToCppBuffer that fails with
-// --force-slow-path.
-// Flags: --no-force-slow-path
 
 d8.file.execute('test/mjsunit/compiler/fast-api-helpers.js');