remove disable signal handler in asan

deps/oblib/src/lib/signal/ob_signal_handlers.cpp

@@ -25,19 +25,16 @@ namespace oceanbase {
 namespace common {
 static const int SIG_SET[] = {SIGABRT, SIGBUS, SIGFPE, SIGSEGV, SIGURG};
 
-#ifndef OB_USE_ASAN
 static inline void handler(int sig, siginfo_t *s, void *p)
 {
   if (tl_handler != nullptr) {
     tl_handler(sig, s, p);
   }
 }
-#endif
 
 int install_ob_signal_handler()
 {
   int ret = OB_SUCCESS;
-#ifndef OB_USE_ASAN
   struct sigaction sa;
   sa.sa_flags = SA_SIGINFO | SA_RESTART | SA_NODEFER | SA_ONSTACK;
   sa.sa_sigaction = handler;
@@ -47,7 +44,6 @@ int install_ob_signal_handler()
       ret = OB_INIT_FAIL;
     }
   }
-#endif
   return ret;
 }