MJIT: Cancel all on disastrous situations (#7019)

I noticed this while running test_yjit with --mjit-call-threshold=1, 
which redefines `Integer#<`. When Ruby is monkey-patched, 
MJIT itself could be broken.

Similarly, Ruby scripts could break MJIT in many different ways. I
prepared the same set of hooks as YJIT so that we could possibly
override it and disable it on those moments. Every constant under
RubyVM::MJIT is private and thus it's an unsupported behavior though.

1 files changed, 11 insertions, 0 deletions

diff --git a/mjit_c.rb b/mjit_c.rb
index d0d4ef168c..905de6139a 100644
--- a/mjit_c.rb
+++ b/mjit_c.rb
@@ -109,6 +109,13 @@ module RubyVM::MJIT # :nodoc: all
       }
     end
 
+    def mjit_cancel_all(reason)
+      Primitive.cstmt! %{
+        mjit_cancel_all(RSTRING_PTR(reason));
+        return Qnil;
+      }
+    end
+
     # Convert encoded VM pointers to insn BINs.
     def rb_vm_insn_decode(encoded)
       Primitive.cexpr! 'INT2NUM(rb_vm_insn_decode(NUM2PTR(encoded)))'
@@ -170,6 +177,10 @@ module RubyVM::MJIT # :nodoc: all
     Primitive.cexpr! %q{ INT2NUM(VM_METHOD_TYPE_ISEQ) }
   end
 
+  def C.RUBY_EVENT_CLASS
+    Primitive.cexpr! %q{ UINT2NUM(RUBY_EVENT_CLASS) }
+  end
+
   def C.SHAPE_CAPACITY_CHANGE
     Primitive.cexpr! %q{ UINT2NUM(SHAPE_CAPACITY_CHANGE) }
   end