Move RubyVM::MJIT to builtin Ruby

just less C code to maintain

common.mk

@@ -1054,6 +1054,7 @@ BUILTIN_RB_SRCS = \
 		$(srcdir)/numeric.rb \
 		$(srcdir)/io.rb \
 		$(srcdir)/marshal.rb \
+		$(srcdir)/mjit.rb \
 		$(srcdir)/pack.rb \
 		$(srcdir)/trace_point.rb \
 		$(srcdir)/warning.rb \
@@ -9430,6 +9431,7 @@ miniinit.$(OBJEXT): {$(VPATH)}mini_builtin.c
 miniinit.$(OBJEXT): {$(VPATH)}miniinit.c
 miniinit.$(OBJEXT): {$(VPATH)}miniprelude.c
 miniinit.$(OBJEXT): {$(VPATH)}missing.h
+miniinit.$(OBJEXT): {$(VPATH)}mjit.rb
 miniinit.$(OBJEXT): {$(VPATH)}nilclass.rb
 miniinit.$(OBJEXT): {$(VPATH)}node.h
 miniinit.$(OBJEXT): {$(VPATH)}numeric.rb
@@ -9652,6 +9654,8 @@ mjit.$(OBJEXT): {$(VPATH)}method.h
 mjit.$(OBJEXT): {$(VPATH)}missing.h
 mjit.$(OBJEXT): {$(VPATH)}mjit.c
 mjit.$(OBJEXT): {$(VPATH)}mjit.h
+mjit.$(OBJEXT): {$(VPATH)}mjit.rb
+mjit.$(OBJEXT): {$(VPATH)}mjit.rbinc
 mjit.$(OBJEXT): {$(VPATH)}mjit_config.h
 mjit.$(OBJEXT): {$(VPATH)}mjit_worker.c
 mjit.$(OBJEXT): {$(VPATH)}node.h

inits.c

@@ -101,6 +101,9 @@ rb_call_builtin_inits(void)
     BUILTIN(yjit);
     BUILTIN(nilclass);
     BUILTIN(marshal);
+#if USE_MJIT
+    BUILTIN(mjit);
+#endif
     Init_builtin_prelude();
 }
 #undef CALL

mjit.c

@@ -375,10 +375,12 @@ mjit_notify_waitpid(int status)
 
 // Return true if given ISeq body should be compiled by MJIT
 static inline int
-mjit_target_iseq_p(struct rb_iseq_constant_body *body)
+mjit_target_iseq_p(const rb_iseq_t *iseq)
 {
+    struct rb_iseq_constant_body *body = ISEQ_BODY(iseq);
     return (body->type == ISEQ_TYPE_METHOD || body->type == ISEQ_TYPE_BLOCK)
-        && !body->builtin_inline_p;
+        && !body->builtin_inline_p
+        && strcmp("<internal:mjit>", RSTRING_PTR(rb_iseq_path(iseq)));
 }
 
 // If recompile_p is true, the call is initiated by mjit_recompile.
@@ -389,7 +391,7 @@ mjit_add_iseq_to_process(const rb_iseq_t *iseq, const struct rb_mjit_compile_inf
     // TODO: Support non-main Ractors
     if (!mjit_enabled || pch_status == PCH_FAILED || !rb_ractor_main_p())
         return;
-    if (!mjit_target_iseq_p(ISEQ_BODY(iseq))) {
+    if (!mjit_target_iseq_p(iseq)) {
         ISEQ_BODY(iseq)->jit_func = (mjit_func_t)NOT_COMPILED_JIT_ISEQ_FUNC; // skip mjit_wait
         return;
     }
@@ -1104,4 +1106,6 @@ mjit_mark_cc_entries(const struct rb_iseq_constant_body *const body)
     }
 }
 
+#include "mjit.rbinc"
+
 #endif // USE_MJIT

mjit.rb

@@ -0,0 +1,13 @@
+module RubyVM::MJIT
+  def self.enabled?
+    Primitive.cexpr! 'RBOOL(mjit_enabled)'
+  end
+
+  def self.pause(wait: true)
+    Primitive.cexpr! 'mjit_pause(RTEST(wait))'
+  end
+
+  def self.resume
+    Primitive.cexpr! 'mjit_resume()'
+  end
+end

vm.c

@@ -3408,36 +3408,6 @@ core_hash_merge_kwd(VALUE hash, VALUE kw)
     return hash;
 }
 
-/* Returns true if JIT is enabled */
-static VALUE
-mjit_enabled_p(VALUE _)
-{
-    return RBOOL(mjit_enabled);
-}
-
-static VALUE
-mjit_pause_m(int argc, VALUE *argv, RB_UNUSED_VAR(VALUE self))
-{
-    VALUE options = Qnil;
-    VALUE wait = Qtrue;
-    rb_scan_args(argc, argv, "0:", &options);
-
-    if (!NIL_P(options)) {
-        static ID keyword_ids[1];
-        if (!keyword_ids[0])
-            keyword_ids[0] = rb_intern("wait");
-        rb_get_kwargs(options, keyword_ids, 0, 1, &wait);
-    }
-
-    return mjit_pause(RTEST(wait));
-}
-
-static VALUE
-mjit_resume_m(VALUE _)
-{
-    return mjit_resume();
-}
-
 extern VALUE *rb_gc_stack_start;
 extern size_t rb_gc_stack_maxsize;
 
@@ -3618,15 +3588,6 @@ Init_VM(void)
     rb_gc_register_mark_object(fcore);
     rb_mRubyVMFrozenCore = fcore;
 
-    /* ::RubyVM::MJIT
-     * Provides access to the Method JIT compiler of MRI.
-     * Of course, this module is MRI specific.
-     */
-    VALUE mjit = rb_define_module_under(rb_cRubyVM, "MJIT");
-    rb_define_singleton_method(mjit, "enabled?", mjit_enabled_p, 0);
-    rb_define_singleton_method(mjit, "pause", mjit_pause_m, -1);
-    rb_define_singleton_method(mjit, "resume", mjit_resume_m, 0);
-
     /*
      * Document-class: Thread
      *