ART: Only run addr2line in abort thread dumps

Avoid addr2line overhead for SIGQUIT and other thread dumps.

Bug: 18933933
Change-Id: I81bb291ede870d1d14b30bb0afdc47830ed14e8b
diff --git a/runtime/utils.cc b/runtime/utils.cc
index d7d4ec2..908cfbd2 100644
--- a/runtime/utils.cc
+++ b/runtime/utils.cc
@@ -1208,7 +1208,7 @@
   if (kUseAddr2line) {
     // Try to run it to see whether we have it. Push an argument so that it doesn't assume a.out
     // and print to stderr.
-    use_addr2line = RunCommand("addr2line -h", nullptr, nullptr);
+    use_addr2line = (gAborting > 0) && RunCommand("addr2line -h", nullptr, nullptr);
   } else {
     use_addr2line = false;
   }