Add more logging output for dlopen.

Investigation of build bot failure which I can not reproduce locally.

Bug: 21854739
Change-Id: I4584bb10ad44e4bcf8232c060e40b36ff924ffa2
diff --git a/runtime/gc/heap.cc b/runtime/gc/heap.cc
index 14fa740..0cdd3c3 100644
--- a/runtime/gc/heap.cc
+++ b/runtime/gc/heap.cc
@@ -503,6 +503,7 @@
     bool no_gap = MemMap::CheckNoGaps(GetImageSpace()->GetMemMap(),
                                       non_moving_space_->GetMemMap());
     if (!no_gap) {
+      PrintFileToLog("/proc/self/maps", LogSeverity::ERROR);
       MemMap::DumpMaps(LOG(ERROR), true);
       LOG(FATAL) << "There's a gap between the image space and the non-moving space";
     }