The blanket `std:#️⃣:Hash` impl for instances of `v8::Data` invokes
`v8::internal::Object::GetHash()` but that crashes for `v8::Module`
objects. Use a custom impl that calls `v8::Module::get_identity_hash()`.
Fixes the following runtime assertion:
# Fatal error in ../../../v8/src/objects/objects-inl.h, line 1043
# Debug check failed: object.IsJSReceiver().
Refs: https://github.com/denoland/deno/pull/8354#discussion_r522157813
After the upgrade some Deno tests started crashing somewhere deep inside
V8, and the cause of these crashes is unclear.
This reverts the following commits:
* 12334ffe Upgrade gn to 6f13aaac; make BUILD.gn compatible with it (#443)
* f53f10d4 Upgrade V8 to 8.7.25 (#443)
Isolate::run_microtasks() already exists but the microtasks queue
is also flushed on script entry and exit. Some embedders want strict
control over when microtasks run, which is set by the policy.
And deprecate Isolate::run_microtasks(). The corresponding V8 API is
tagged with V8_DEPRECATE_SOON.
After upgrading to V8 8.6.337, with a 20 MB heap limit, the
near-heap-limit callback never gets called before V8 runs out of memory.
It turns out that this test exhibits memory allocation behavior which
produces so little actual garbage that 'scavenge' type garbage
collections make memory usage go up rather than down. Because of this,
V8 runs out of memory in the middle of a garbage collection cycle, after
it has already decided that there's no need to run the near-heap-limit
callback.
The issue is fixed by making sure that some actual garbage is produced
alongside with the retained objects that will eventually fill up the
heap.
* Merged all handle type implementations into one file ('handle.h').
* Made it so that `Global` handles cannot be empty.
* Renamed the `AsHandle` trait to `Handle`, and made it more generally
useful.
* Simplified how `PartialEq` is implemented for V8 heap objects and/or
the `Local`/`Global` handles that reference them.
Local handles never need to be mutable. This patch also rounds up the
last few places where we were still asking the user to pass an `&mut T`
to an API method.
