## Why?
The explanation of x and y is reversed.

https://github.com/ruby/ruby/blob/ddbd64400199fd408d23c85f9fb0d7f742ecf9e1/re.c#L251-L256
```
long
rb_memsearch(const void *x0, long m, const void *y0, long n, rb_encoding *enc)
{
    const unsigned char *x = x0, *y = y0;

    if (m > n) return -1;
```

```
../../.././include/ruby/internal/special_consts.h:349:36: error: conversion to ‘VALUE’ {aka ‘long unsigned int’} from ‘int’ may change the sign of the result [-Werror=sign-conversion]
  349 |     return RB_SPECIAL_CONST_P(obj) * RUBY_Qtrue;
      |            ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~
```

Since 730e3b2ce01915c4a98b79bb281b2c38a9ff1131
("Stop exposing `rb_str_chilled_p`"), we noticed a speed loss on a few
benchmarks that are string operations heavy. This is partially due to
routines no longer having the options to inline rb_check_frozen_inline()
in non-LTO builds. Make it an inlining candidate again to recover speed.

Testing this patch on my machine, the fannkuchredux benchmark gets a
1.15 speed-up with YJIT and 1.03 without YJIT.

And move it back to a public header because Doxygen might not be
scanning the .c files.

[Feature #18776]

[Feature #20589]

This feature is no longer possible under current design; now that our GC
is pluggable, we cannot assume what was achieved by this compiler flag
is always possble by the dynamically-loaded GC implementation.

This function accepts flags:

RB_NO_KEYWORDS, RB_PASS_KEYWORDS, RB_PASS_CALLED_KEYWORDS:
Works as the same as rb_block_call_kw.

RB_BLOCK_NO_USE_PACKED_ARGS:
The given block ("bl_proc") does not use "yielded_arg" of rb_block_call_func_t.
Instead, the block accesses the yielded arguments via "argc" and "argv".
This flag allows the called method to yield arguments without allocating an Array.

Previously, RBIMPL_ASSERT_TYPE() used Check_Type() only in RUBY_DEBUG
builds. It raised TypeError, but only in debug builds. For people testing
type mismatch using debug builds looking for a Ruby exception, this can
be misleading -- the code could be missing a type check in non-debug builds
if it is relying on for example RSTRING_LEN() to raise.

Also, Check_Type() can obscure the true cause of error in debug mode.
When type check fails because the object is corrupt, instead of crashing
with a clear type assertion message, it can crash while trying to
construct an exception object to raise. You can see this for example in
<https://github.com/ruby/ruby/actions/runs/9489999591/job/26152506434?pr=10985>,
where RB_ENCODING_GET() is used on a corrupt object, but the crash
happens later and says "Assertion Failed:
../src/vm_method.c:1477:callable_method_entry_or_negative".
RBIMPL_ASSERT_TYPE() should assert right away.

RBIMPL_ASSERT_OR_ASSUME() asserts when RUBY_DEBUG and assumes in release
builds, as desired.

This should help investigate flaky CI failures that show up as TypeError
from `Kernel#require`, e.g.
"'Kernel#require': wrong argument type false (expected String) (TypeError)".

Same CI failure examples:
 - https://github.com/ruby/ruby/actions/runs/9034787861/job/24828147431
 - https://github.com/ruby/ruby/actions/runs/9418303667/job/25945492440
 - https://github.com/ruby/ruby/actions/runs/9505650952/job/26201031314

The failure occurs with and without use of YJIT.