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/thread.cc b/runtime/thread.cc
index 22f0e80..b524f34 100644
--- a/runtime/thread.cc
+++ b/runtime/thread.cc
@@ -495,7 +495,9 @@
   }
 
   // TODO: move this into the Linux GetThreadStack implementation.
-#if !defined(__APPLE__)
+#if defined(__APPLE__)
+  bool is_main_thread = false;
+#else
   // If we're the main thread, check whether we were run with an unlimited stack. In that case,
   // glibc will have reported a 2GB stack for our 32-bit process, and our stack overflow detection
   // will be broken because we'll die long before we get close to 2GB.