Avoid checking interrupt when loading iseq

The interrupt check will unintentionally release the VM lock when loading an iseq.
And this will cause issues with the `debug` gem's
[`ObjectSpace.each_iseq` method](https://github.com/ruby/debug/blob/0fcfc28acae33ec1c08068fb7c33703cfa681fa7/ext/debug/iseq_collector.c#L61-L67),
which wraps iseqs with a wrapper and exposes their internal states when they're actually not ready to be used.

And when that happens, errors like this would occur and kill the `debug` gem's thread:

```
 DEBUGGER: ReaderThreadError: uninitialized InstructionSequence
┃ DEBUGGER: Disconnected.
┃ ["/opt/rubies/ruby-3.2.0/lib/ruby/gems/3.2.0/gems/debug-1.7.1/lib/debug/breakpoint.rb:247:in `absolute_path'",
┃  "/opt/rubies/ruby-3.2.0/lib/ruby/gems/3.2.0/gems/debug-1.7.1/lib/debug/breakpoint.rb:247:in `block in iterate_iseq'",
┃  "/opt/rubies/ruby-3.2.0/lib/ruby/gems/3.2.0/gems/debug-1.7.1/lib/debug/breakpoint.rb:246:in `each_iseq'",
...
```

A way to reproduce the issue is to satisfy these conditions at the same time:

1. `debug` gem calling `ObjectSpace.each_iseq` (e.g. [activating a `LineBreakpoint`](https://github.com/ruby/debug/blob/0fcfc28acae33ec1c08068fb7c33703cfa681fa7/lib/debug/breakpoint.rb#L246)).
2. A large amount of iseq being loaded from another thread (possibly through the `bootsnap` gem).
3. 1 and 2 iterating through the same iseq(s) at the same time.

Because this issue requires external dependencies and a rather complicated timing setup to reproduce, I wasn't able to write a test case for it.
But here's some pseudo code to help reproduce it:

```rb
require "debug/session"

Thread.new do
  100.times do
    ObjectSpace.each_iseq do |iseq|
      iseq.absolute_path
    end
  end
end

sleep 0.1

load_a_bunch_of_iseq
possibly_through_bootsnap
```

[Bug #19348]

Co-authored-by: Peter Zhu <[email protected]>

1 files changed, 11 insertions, 0 deletions

diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index 29753f1800..0ce7fb6cc7 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -405,6 +405,17 @@ vm_push_frame(rb_execution_context_t *ec,
     vm_push_frame_debug_counter_inc(ec, cfp, type);
 }
 
+void
+rb_vm_pop_frame_no_int(rb_execution_context_t *ec)
+{
+    rb_control_frame_t *cfp = ec->cfp;
+
+    if (VM_CHECK_MODE >= 4) rb_gc_verify_internal_consistency();
+    if (VMDEBUG == 2)       SDR();
+
+    ec->cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp);
+}
+
 /* return TRUE if the frame is finished */
 static inline int
 vm_pop_frame(rb_execution_context_t *ec, rb_control_frame_t *cfp, const VALUE *ep)