Fix compilation for OPT_THREADED_CODE=2

tool/ruby_vm/views/vm.inc.erb

@@ -25,16 +25,19 @@
 <%= render 'insn_entry', locals: { insn: insn } -%>
 % end
 %
-% RubyVM::TraceInstructions.to_a.each do |insn|
-<%= render 'trace_instruction', locals: { insn: insn } -%>
-% end
 % RubyVM::MicroJIT::ExampleInstructions.to_a.each do |insn|
 INSN_ENTRY(<%= insn.name %>)
 {
     START_OF_ORIGINAL_INSN(<%= insn.name %>);
+#if USE_MACHINE_REGS
     // assumes USE_MACHINE_REGS, aka reg_pc setup,
     // aka #define SET_PC(x) (reg_cfp->pc = reg_pc = (x))
     reg_pc = rb_ujit_empty_func(GET_CFP());
+#endif
     END_INSN(<%= insn.name %>);
 }
 % end
+%
+% RubyVM::TraceInstructions.to_a.each do |insn|
+<%= render 'trace_instruction', locals: { insn: insn } -%>
+% end

vm_opts.h

@@ -34,7 +34,7 @@
  * 2: call (function call for each insn dispatch)
  */
 #ifndef OPT_THREADED_CODE
-#define OPT_THREADED_CODE 0
+#define OPT_THREADED_CODE 2
 #endif
 
 #define OPT_DIRECT_THREADED_CODE (OPT_THREADED_CODE == 0)