[compiler-rt][hwasan] Call __hwasan_library_loaded via __sanitizer_library_loaded on Fuchsia

[phosek]

LGTM

[mcgrathr]

We haven't quite worked out this signature on the Fuchsia side yet.
Also, this makes the dl_iterate_phdr sequence in InitLoadedGlobals redundant so we should remove that for the Fuchsia configurations.

[leonardchan]

*ping* @mcgrathr Does this LGTY? D137676 also removes the redundant InitLoadedGlobals call.

[mcgrathr]

lgtm

compiler-rt/lib/hwasan/hwasan_fuchsia.cpp

 void __sanitizer_thread_start_hook(void *hook, thrd_t self) {
   __hwasan::ThreadStartHook(hook, reinterpret_cast<uptr>(self));
 }
 
 void __sanitizer_thread_exit_hook(void *hook, thrd_t self) {
   __hwasan::ThreadExitHook(hook, self);
 }
 
+void __sanitizer_module_loaded(const struct dl_phdr_info *info, size_t) {
+  __hwasan_library_loaded(info->dlpi_addr, info->dlpi_phdr, info->dlpi_phnum);
+}
+
 }  // extern "C"
 
 #endif  // SANITIZER_FUCHSIA