Remove mirror:: and ArtMethod deps in utils.{h,cc}

The latest chapter in the ongoing saga of attempting to dump a DEX
file without having to start a whole runtime instance.  This episode
finds us removing references to ArtMethod/ArtField/mirror.

One aspect of this change that I would like to call out specfically
is that the utils versions of the "Pretty*" functions all were written
to accept nullptr as an argument.  I have split these functions up as
follows:
1) an instance method, such as PrettyClass that obviously requires
this != nullptr.
2) a static method, that behaves the same way as the util method, but
calls the instance method if p != nullptr.
This requires using a full class qualifier for the static methods,
which isn't exactly beautiful.  I have tried to remove as many cases
as possible where it was clear p != nullptr.

Bug: 22322814
Test: test-art-host
Change-Id: I21adee3614aa697aa580cd1b86b72d9206e1cb24
diff --git a/runtime/mirror/array-inl.h b/runtime/mirror/array-inl.h
index 3789081..b11dad8 100644
--- a/runtime/mirror/array-inl.h
+++ b/runtime/mirror/array-inl.h
@@ -168,7 +168,7 @@
   // 32-bit.
   if (UNLIKELY(size == 0)) {
     self->ThrowOutOfMemoryError(StringPrintf("%s of length %d would overflow",
-                                             PrettyDescriptor(array_class).c_str(),
+                                             array_class->PrettyDescriptor().c_str(),
                                              component_count).c_str());
     return nullptr;
   }