Clean up Handle usage.

Prefer using ConstHandle instead of Handle as function arguments
since you can't assign new references to ConstHandle which helps
prevent bugs.

Changed NullHandle to be a ConstHandle so that you can never modify
it to be a non null reference.

Change-Id: I81cb979f6f8d5b49e5614966a2caf28c3701dd4f
diff --git a/runtime/quick_exception_handler.cc b/runtime/quick_exception_handler.cc
index 1e933a2..1ec488e 100644
--- a/runtime/quick_exception_handler.cc
+++ b/runtime/quick_exception_handler.cc
@@ -211,9 +211,9 @@
     Handle<mirror::DexCache> h_dex_cache(hs.NewHandle(declaring_class->GetDexCache()));
     Handle<mirror::ClassLoader> h_class_loader(hs.NewHandle(declaring_class->GetClassLoader()));
     Handle<mirror::ArtMethod> h_method(hs.NewHandle(m));
-    verifier::MethodVerifier verifier(h_dex_cache->GetDexFile(), &h_dex_cache, &h_class_loader,
-                                      &m->GetClassDef(), code_item, m->GetDexMethodIndex(), h_method,
-                                      m->GetAccessFlags(), false, true, true);
+    verifier::MethodVerifier verifier(h_dex_cache->GetDexFile(), h_dex_cache, h_class_loader,
+                                      &m->GetClassDef(), code_item, m->GetDexMethodIndex(),
+                                      h_method, m->GetAccessFlags(), false, true, true);
     verifier.Verify();
     const std::vector<int32_t> kinds(verifier.DescribeVRegs(dex_pc));
     for (uint16_t reg = 0; reg < num_regs; ++reg) {