ART: Fix things for valgrind

Wire up valgrind gtests. Add valgrind-test-art-host, currently
only depending on valgrind-test-art-host-gtest32.

Fix an Alloc setting to allow running valgrind.

Refactor the fault handler to manage (and correctly release) the
handlers.

Fix minor failure-case leaks exposed by tests.

Failing tests:

The optimizing compiler is leaking non-arena-ed structures
(e.g., assembler buffers), as code generators are not destroyed.
The solution has been moved to a follow-up CL.

Note: All 64b tests are failing as we cannot allocate a heap.

Change-Id: I7f854cfd098d9f68107ce492363e7dba9a82b9fa
diff --git a/compiler/driver/compiler_driver.cc b/compiler/driver/compiler_driver.cc
index 32a7676..db6a01e 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -981,7 +981,7 @@
 
   ScopedObjectAccess soa(Thread::Current());
   mirror::Class* reference_class = mirror::Reference::GetJavaLangRefReference();
-  bool is_initialized;
+  bool is_initialized = false;
   bool unused_finalizable;
   // Make sure we have a finished Reference class object before attempting to use it.
   if (!CanEmbedTypeInCode(*reference_class->GetDexCache()->GetDexFile(),