suppress meddlesome clang10 warrning

It says:

vm.c:2519:34: warning: expression does not compute the number of elements in this array; element type is 'const struct __jmp_buf_tag', not 'VALUE' (aka 'unsigned long') [-Wsizeof-array-div]
                             sizeof(ec->machine.regs) / sizeof(VALUE));
                                    ~~~~~~~~~~~~~~~~  ^
vm.c:2519:34: note: place parentheses around the 'sizeof(VALUE)' expression to silence this warning

1 files changed, 1 insertions, 1 deletions

diff --git a/vm.c b/vm.c
index b76f9204ab..f26ab73dfe 100644
--- a/vm.c
+++ b/vm.c
@@ -2516,7 +2516,7 @@ rb_execution_context_mark(const rb_execution_context_t *ec)
 	rb_gc_mark_machine_stack(ec);
 	rb_gc_mark_locations((VALUE *)&ec->machine.regs,
 			     (VALUE *)(&ec->machine.regs) +
-			     sizeof(ec->machine.regs) / sizeof(VALUE));
+			     sizeof(ec->machine.regs) / (sizeof(VALUE)));
     }
 
     RUBY_MARK_UNLESS_NULL(ec->errinfo);