fix the module map of main executable on darwin platforms

skip the __PAGEZERO segment when calculate image range

Author: pudge62

compiler-rt/lib/sanitizer_common/sanitizer_procmaps_mac.cpp

@@ -433,7 +433,9 @@ void MemoryMappingLayout::DumpListOfModules(
   MemoryMappedSegmentData data;
   segment.data_ = &data;
   while (Next(&segment)) {
-    if (segment.filename[0] == '\0') continue;
+    // skip the __PAGEZERO segment, its vmsize is 0
+    if (segment.filename[0] == '\0' || (segment.start == segment.end))
+      continue;
     LoadedModule *cur_module = nullptr;
     if (!modules->empty() &&
         0 == internal_strcmp(segment.filename, modules->back().full_name())) {