RUBY_VM_CHECK_INTS: eval the argument only once

* vm_core.h (RUBY_VM_CHECK_INTS): evaluate the argument only once
  to get rid of inadvertent side effects.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51281 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

vm_core.h

@@ -1090,11 +1090,14 @@ void rb_threadptr_pending_interrupt_clear(rb_thread_t *th);
 void rb_threadptr_pending_interrupt_enque(rb_thread_t *th, VALUE v);
 int rb_threadptr_pending_interrupt_active_p(rb_thread_t *th);
 
-#define RUBY_VM_CHECK_INTS(th) do { \
-    if (UNLIKELY(RUBY_VM_INTERRUPTED_ANY(th))) {	\
-	rb_threadptr_execute_interrupts(th, 0); \
-    } \
-} while (0)
+#define RUBY_VM_CHECK_INTS(th) ruby_vm_check_ints(th)
+static inline void
+ruby_vm_check_ints(rb_thread_t *th)
+{
+    if (UNLIKELY(RUBY_VM_INTERRUPTED_ANY(th))) {
+	rb_threadptr_execute_interrupts(th, 0);
+    }
+}
 
 /* tracer */
 struct rb_trace_arg_struct {