Remove deprecated WITH_HOST_DALVIK.

Bug: 13751317
Fix the Mac build:
 - disable x86 selector removal that causes OS/X 10.9 kernel panics,
 - madvise don't need does zero memory on the Mac, factor into MemMap
   routine,
 - switch to the elf.h in elfutils to avoid Linux kernel dependencies,
 - we can't rely on exclusive_owner_ being available from other pthread
   libraries so maintain our own when futexes aren't available (we
   can't rely on the OS/X 10.8 hack any more),
 - fix symbol naming in assembly code,
 - work around C library differences,
 - disable backtrace in DumpNativeStack to avoid a broken libbacktrace
   dependency,
 - disable main thread signal handling logic,
 - align the stack in stub_test,
 - use $(HOST_SHLIB_SUFFIX) rather than .so in host make file variables.

Not all host tests are passing on the Mac with this change. dex2oat
works as does running HelloWorld.
Change-Id: I5a232aedfb2028524d49daa6397a8e60f3ee40d3
diff --git a/runtime/utils.cc b/runtime/utils.cc
index 7700658..f60f795 100644
--- a/runtime/utils.cc
+++ b/runtime/utils.cc
@@ -1054,6 +1054,7 @@
   if (current_method != nullptr) {
     Locks::mutator_lock_->AssertSharedHeld(Thread::Current());
   }
+#ifdef __linux__
   std::unique_ptr<Backtrace> backtrace(Backtrace::Create(BACKTRACE_CURRENT_PROCESS, tid));
   if (!backtrace->Unwind(0)) {
     os << prefix << "(backtrace::Unwind failed for thread " << tid << ")\n";
@@ -1095,6 +1096,7 @@
     }
     os << "\n";
   }
+#endif
 }
 
 #if defined(__APPLE__)