Push a real iseq in rb_vm_push_frame_fname()

	Previously, vm_make_env_each() (used during proc
	creation and for the debug inspector C API) picked up the
	non-GC-allocated iseq that rb_vm_push_frame_fname() creates,
	which led to a SEGV when the GC tried to mark the non GC object.

	Put a real iseq imemo instead. Speed should be about the same since
	the old code also did a imemo allocation and a malloc allocation.

	Real iseq allows ironing out the special-casing of dummy frames in
	rb_execution_context_mark() and rb_execution_context_update(). A check
	is added to RubyVM::ISeq#eval, though, to stop attempts to run dummy
	iseqs.

	[Bug #21180]

	Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>

	Ensure fiber scheduler re-acquires mutex when interrupted from sleep. (#12158)

	[Bug #20907]

	Enumerator should use a non-blocking fiber, change `rb_fiber_new` to be non-blocking by default. (#10481)

	test/fiber/test_queue.rb: Make the stuck test fail. (#8791)

	test/fiber/test_queue.rb: Make the stuck tests fail.

	We observed the 2 tests in the `test/fiber/test_queue.rb` getting stuck
	in some GCC compilers in Ubuntu ppc64le focal/jammy, even when the timeout
	`queue.pop(timeout: 0.0001)` is set in the code.

	This commit is to make the tests fail rather than getting stuck.
	---
	 test/fiber/test_queue.rb | 20 ++++++++++++++++----
	 1 file changed, 16 insertions(+), 4 deletions(-)

	Validate the typed data before dereferencing the internal struct.
	 (#8315)

	---
	 process.c                  |  5 +++--
	 test/fiber/test_process.rb | 21 +++++++++++++++++++++
	 2 files changed, 24 insertions(+), 2 deletions(-)

	Fix `Thread#join(timeout)` when running inside the fiber scheduler.
	 (#7903)

	---
	 test/fiber/test_thread.rb | 22 ++++++++++++++++++++++
	 thread.c                  |  5 +++++
	 2 files changed, 27 insertions(+)

	`rb_io_puts` should not write zero length strings. (#7806)

	---
	 io.c                  | 40 ++++++++++++++++++++++++----------------
	 test/fiber/test_io.rb | 28 ++++++++++++++++++++++++++++
	 2 files changed, 52 insertions(+), 16 deletions(-)

	Fix incorrect usage of `rb_fiber_scheduler_io_(p)(read|write)`.
	 (#7593)

	---
	 io_buffer.c                  |  8 ++++----
	 scheduler.c                  | 48 ++++++++++++++++++++++----------------------
	 test/fiber/test_io_buffer.rb | 33 ++++++++++++++++++++++++++++++
	 3 files changed, 61 insertions(+), 28 deletions(-)