As part of JDK-8190308 the following code was added to os_posix.cpp (in os::create_file_for_heap):

48153: sigset_t set, oldset;
48153: int ret = sigfillset(&set);
48153: assert_with_errno(ret == 0, "sigfillset returned error");

The "set" and "oldset" variables are not used later in the function, and sigfillset only affects the "set" variable, so this code is effectively a no-op.