(https://github.com/ruby/fiddle/pull/127)

Save from having to mark them on every minor.

https://github.com/ruby/fiddle/commit/153c09c99f

Co-authored-by: Jean Boussier <jean.boussier@gmail.com>

(https://github.com/ruby/fiddle/pull/123)

This commit adds two new methods, `Fiddle::Pointer.read` and
`Fiddle::Pointer.write`. Both methods take an address, and will read or
write bytes at that address respectively.

For example we can read from an address without making a Pointer object:

```ruby
Fiddle::Pointer.read(address, 5) # read 5 bytes
```

We can also write to an address without allocating a Pointer object:

```ruby
Fiddle::Pointer.write(address, "bytes") # write 5 bytes
```

This allows us to read / write memory at arbitrary addresses without
instantiating a new `Fiddle::Pointer` object.

Examples where this API would be useful
[1](https://github.com/tenderlove/tenderjit/blob/f03481d28bff4d248746e596929b0841de65f181/lib/tenderjit/fiddle_hacks.rb#L26-L28)
[2](https://github.com/tenderlove/ruby/blob/77c8daa2d40dd58eeb3785ce17dea2ee38f308d1/lib/ruby_vm/rjit/c_pointer.rb#L193)
[3](https://github.com/tenderlove/ruby/blob/77c8daa2d40dd58eeb3785ce17dea2ee38f308d1/lib/ruby_vm/rjit/c_pointer.rb#L284)

I also added a writer method for the same reasons as the reader.

---------

https://github.com/ruby/fiddle/commit/04238cefed

Co-authored-by: Sutou Kouhei <kou@clear-code.com>

https://github.com/ruby/fiddle/commit/c5abcc3a7e

https://github.com/ruby/fiddle/commit/170111a0cb

Fix https://github.com/ruby/fiddle/pull/84

It may detect ruby/memory_view.h for system Ruby that is installed in
/usr.

We can use RUBY_API_VERSION_MAJOR to detect memory view availability
because memory view is available since Ruby 3.0.

Reported by Jun Aruga. Thanks!!!

https://github.com/ruby/fiddle/commit/3292929830

https://github.com/ruby/fiddle/commit/bddca7c895

I don't use tool/sync_default_gem.rb because the last sync was incomplete.

Co-authored-by: Hiroshi SHIBATA <hsbt@ruby-lang.org>
Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>
Co-authored-by: sinisterchipmunk <sinisterchipmunk@gmail.com>
Co-authored-by: Sutou Kouhei <kou@clear-code.com>

* Add a "pinning" reference

A `Fiddle::Pinned` objects will prevent the objects they point to from
moving.  This is useful in the case where you need to pass a reference
to a C extension that keeps the address in a global and needs the
address to be stable.

For example:

```ruby
class Foo
  A = "hi" # this is an embedded string

  some_c_function A # A might move!
end
```

If `A` moves, then the underlying string buffer may also move.
`Fiddle::Pinned` will prevent the object from moving:

```ruby
class Foo
  A = "hi" # this is an embedded string

  A_pinner = Fiddle::Pinned.new(A) # :nodoc:

  some_c_function A # A can't move because of `Fiddle::Pinned`
end
```

This is a similar strategy to what Graal uses:

  https://www.graalvm.org/sdk/javadoc/org/graalvm/nativeimage/PinnedObject.html#getObject--

* rename global to match exception name

* Introduce generic Fiddle::Error and rearrange error classes

Fiddle::Error is the generic exception base class for Fiddle exceptions.
This commit introduces the class and rearranges Fiddle exceptions to
inherit from it.

https://github.com/ruby/fiddle/commit/ac52d00223

https://github.com/ruby/fiddle/commit/e59cfd708a