ref. commit 7f40b645

Currently, the build configurations `MRB_USE_COMPLEX` and `MRB_USE_RATIONAL` are not listed in the documentation.
In other words, they are hidden settings.
They are defined in `mrbgems/mruby-{complex,rational}/mrbgem.rake`.
So this patch assumes that it is safe to refer to these functions in core-gems directly from core functions.

However, applications that link with `libmruby_core.a` will have compatibility issues.
In fact, `mrbgems/mruby-bin-mrbc` links with `libmruby_core.a`, so I had to prepare a dummy function.

Extend the Cygwin CI time limit to 15 minutes.

Get object properties after `mrb_get_args()`

Since they are basically duplicated functionality. `mrb_as_float` is now
a macro defined using `mrb_ensure_float_type`; #5620

It should only call `to_f` for Rational and Complex numbers.
Ref #5540 #5613 #5620

That reduce memory consumption by iv/mt tables.

The main reason for failure is to exceed the time limit, and even when it succeeds, there is less than a minute left.
The 10-minute time limit seems to be too short.

ref. #5613

I checked with Valgrind, and the methods that can cause use-after-free are `Array#rotate`, `Array#rotate!`, and `String#byteslice`.
Since `String#rindex` uses `RSTRING_LEN()` indirectly inside the function, no reference to the out-of-bounds range is generated.

Since `mrb_to_integer` and `mrb_to_float` does not convert the object
but checks types, they are named so by historical reason. We introduced
properly named functions.

This commit obsoletes the following functions:

* mrb_to_integer()
* mrb_to_int()
* mrb_to_float()

Use `mrb_ensure_int_type()` instead for the first 2 functions. Use
`mrb_ensure_float_type()` for the last.

mruby have removed `to_int` implicit conversion, so `mrb_to_integer`
should not call `to_i` for conversion.

The `ARY_PTR` and `ARY_LEN` may be modified in `mrb_get_args`.

Fix build error and refine definition of `ssize_t` on MSVC.

Fix word casing in the README

pre-commit autoupdate

https://pre-commit.com/#pre-commit-autoupdate

Changed `Actual` to `actual` mid sentence

Fix summary typo for `mrbgems/mruby-compar-ext`

Allow void expression on some places e.g. right hand of `rescue`
modifier. In addition, checks added on some places, e.g. left hand of
logical operators.

build(deps): bump github/super-linter from 4.8.4 to 4.8.5

Bumps [github/super-linter](https://github.com/github/super-linter) from 4.8.4 to 4.8.5.
- [Release notes](https://github.com/github/super-linter/releases)
- [Changelog](https://github.com/github/super-linter/blob/main/docs/release-process.md)
- [Commits](https://github.com/github/super-linter/compare/v4.8.4...v4.8.5)

---
updated-dependencies:
- dependency-name: github/super-linter
  dependency-type: direct:production
  update-type: version-update:semver-patch
...
Signed-off-by: dependabot[bot] <support@github.com>

Note that the current implantation only calls `[]=` method. No
performance improvement. Just 2 bytes less byte code per assignment.

Add `bin/mrbc --no-ext-ops` switch

Print error before cleanup in `codegen_error()`

Previously, it always pointed to the highest scope as the location of the error.

  - example code `code.rb`

    ```ruby
    huge_num = "1" + "0" * 300; eval <<CODE, nil, "test.rb", 1
    class Object
      module A
        #{huge_num}
      end
    end
    CODE
    ```

  - Before this patch

    ```console
    % bin/mruby code.rb
    test.rb:1: integer too big
    trace (most recent call last):
            [1] code.rb:1
    code.rb:1:in eval: codegen error (ScriptError)
    ```

  - After this patch

    ```console
    % bin/mruby code.rb
    test.rb:3: integer too big
    trace (most recent call last):
            [1] code.rb:1
    code.rb:1:in eval: codegen error (ScriptError)
    ```

Print an error if `OP_EXT[123]` is needed when generating mruby binary.
This may be useful for mruby/c.

Inspired by #5590.

build(deps): bump actions/upload-artifact from 2.2.4 to 2.3.1