Add message for assert

Not all C++ stds implement it w/o.

Author: thesamesam

src/hotspot/os/linux/attachListener_linux.cpp

@@ -184,7 +184,7 @@ int LinuxAttachListener::init() {
   char initial_path[UNIX_PATH_MAX];  // socket file during setup
   int listener;                      // listener socket (file descriptor)
 
-  static_assert(sizeof(off_t) == 8);
+  static_assert(sizeof(off_t) == 8, "Expected Large File Support in this file");
 
   // register function to cleanup
   if (!_atexit_registered) {

src/hotspot/os/linux/os_linux.cpp

@@ -2772,7 +2772,7 @@ void os::jvm_path(char *buf, jint buflen) {
 void linux_wrap_code(char* base, size_t size) {
   static volatile jint cnt = 0;
 
-  static_assert(sizeof(off_t) == 8);
+  static_assert(sizeof(off_t) == 8, "Expected Large File Support in this file");
 
   if (!UseOprofile) {
     return;

src/hotspot/os/posix/os_posix.cpp

@@ -287,7 +287,7 @@ static char* reserve_mmapped_memory(size_t bytes, char* requested_addr) {
 }
 
 static int util_posix_fallocate(int fd, off_t offset, off_t len) {
-  static_assert(sizeof(off_t) == 8);
+  static_assert(sizeof(off_t) == 8, "Expected Large File Support in this file");
 #ifdef __APPLE__
   fstore_t store = { F_ALLOCATECONTIG, F_PEOFPOSMODE, 0, len };
   // First we try to get a continuous chunk of disk space