Implement new `StableApiDefinition` VM control methods

[ianks]

In order to support Truffleruby on magnus, we need to support VM control operations, which currently relies on cruby internals.

/// Causes the interpreter to abort with a message. This function never
/// returns (akin to `rb_bug`).
///
/// **Important**: This function is an absolute last resort. It should
/// only be used if all else fails.
fn vm_panic(&self, message: &CStr) -> !;

/// Issues a warning using Ruby's `warn` function (akin to `rb_warning`).
fn vm_warning(msg: &CStr);

[eregon]

rb_bug/rb_warn/rb_warning are all implemented on TruffleRuby (as static inline functions) so this should be straightforward. What is used currently for CRuby? I'd imagine it's the same functions so ideally it'd work the same for both.

If the static inline functions are a problem and you need non-static functions, there might be a solution on truffleruby's side, mentioned at the end of https://github.com/oracle/truffleruby/issues/3396#issuecomment-2580778963