If no block is given and the Range has Fixnum or Float endpoints, do not iterate with
each and instead compare the endpoints directly. This implementation passes all of
the applicable specs from Ruby Spec.

This patch prevents a hang for pathalogical (large) Ranges when
computing max and min.

Range inherits its implementation of max and min from Enumerable.
Enumerable implements max and min by calling each. For Range objects,
this is unnecessary since we know the max and the min by the end and
begin attributes.

It is also very slow. This code hangs unnecessarily:

    (0..2**32).max
    # ... hang
    (0..2**32).min
    # ... hang

This patch overrides max and min after including enumerable to yield
based on the begin and end methods.

Range#each depends on String#upto which is implemented in mruby-string-ext
which is why these tests live there.

Add macros for inline symbol for readability

Fix `Numeric#step` to infinity; ref. #4555

Fix missing `#ifndef MRB_ENABLE_ALL_SYMBOLS`

Merge pull request #4553 from shuujii/read-write-MRB_STR_ASCII-flag-only-when-MRB_UTF8_STRING-is-defined

Read/write `MRB_STR_ASCII` flag only when `MRB_UTF8_STRING` is defined

In #4550, @shuuji proposed the name name `MRB_STR_NO_MULTI_BYTE` for
more precise description. Although I agree that the name name is
correct, but the flag means the string does not contain multi byte UTF-8
characters, i.e. all characters fit in the range of ASCII.

Fix heap buffer overflow; ref #4549

This patch is showed in #4549.

Refine document to mrb_get_args()` [ci skip]

Fix and refine error message in `mrb_obj_to_sym()`

Before this patch:

  $ bin/mruby -e '1.respond_to?(2)'  #=> nil is not a symbol

After this patch (same as Ruby):

  $ bin/mruby -e '1.respond_to?(2)'  #=> 2 is not a symbol nor a string

Remove unused C header file from `src/etc.c`

Fix `include`, `prepend` and `extend` to frozen object

Nested `assert` for mrbtest

Replace `String#[]=` method by C implements

It is integration with part of argument parsing used in `mrb_str_aset_m()`.

The purpose is to eliminate string objects that are temporarily created during processing.

Ref commit 35319bed

When nesting `assert` used in test, it is indented and displayed.
Assertion numbers are concatenated by `"-"` at this time.

The purpose is to match the apparent numbers when failing with `assert_mruby`
which is defined by `mrbgems/mruby-bin-mruby/bintest/mruby.rb` for example.

Child assertions "skip" and "info" are reported as parent assertions "info"
and `$ok_test += 1`. The child assertions "ko" and "crash" are reported as the
parent assertion "ko" and `$ko_test += 1`.

When child assertions are mixed, "ko" takes precedence.

Incompatibility:

- `$mrbtest_assert_idx` takes `nil` or an integer array object.
  So far it was `nil` or an integer.
- `$asserts` points to the top of the internal stack in the `assert`.
- `$mrbtest_assert` points to the top of the internal stack in `assert`.

Use `__ENCODING__` in tests

Remove unnecessary backticks in `src/range.c`; ref #2858

It cannot be used for `String#size` test if judging whether or not `MRB_UTF8_STRING` is defined by result of `String#size`.

Add modification tests for immediate value

Fix broken links for mruby.org