Make use of profiling information for dex2oat

If the profile file exists, the compiler driver will read it
and store the data in an internal map.  Then, when we want to work
out whether to compile a method or not, the map is consulted and if
the method shows up with a high enough percentage of use we compile it.

The profile file itself is created by installd and is writeable by the
app.  The file is in /data/dalvik-cache/profiles and is named by
the package name.

This also modifies the profiler itself to:

1. Only count runnable threads (not suspended threads) in the profile
2. Use system properties to allow tuning of the profile parameters
3. Merge profiles from multiple processes using file locking.

Bug: 12877748
Change-Id: Iab2f3a327a2860db2a80d5724277d6c626227f2b

Conflicts:
	compiler/dex/frontend.cc
	compiler/dex/mir_analysis.cc
	compiler/dex/verification_results.cc
	compiler/driver/compiler_driver.cc
	dex2oat/dex2oat.cc
	runtime/class_linker.cc
	runtime/runtime.cc
	runtime/runtime.h
diff --git a/compiler/dex/mir_graph.h b/compiler/dex/mir_graph.h
index 85d6d89..94b3816 100644
--- a/compiler/dex/mir_graph.h
+++ b/compiler/dex/mir_graph.h
@@ -383,6 +383,11 @@
   bool SkipCompilation();
 
   /*
+   * Should we skip the compilation of this method based on its name?
+   */
+  bool SkipCompilation(const std::string& methodname);
+
+  /*
    * Parse dex method and add MIR at current insert point.  Returns id (which is
    * actually the index of the method in the m_units_ array).
    */