ART: Use libbase logging

Move most of our logging infrastructure over to system/core/base.
Retain VLOG.

Using unified Android infrastructure has two main advantages. First,
it reduces the complexity/maintenance burden in ART. Second, it
allows to detach logging for the cases where we do not want or need
a runtime, e.g., dexdump, the disassembler, etc. As a part of the
latter, libbase is also supported for all hosts (including Windows).

From a developer viewpoint, there are minor behavior changes for the
LOG statements (see above), but otherwise usage is the same. Explicit
severity enum items are in the android::base namespace now.

Bug: 31338270
Test: m test-art-host
Change-Id: I5abcb2f45f5b03d49951874c48544f72a283a91b
diff --git a/runtime/monitor.cc b/runtime/monitor.cc
index 22cc197..49b83a7 100644
--- a/runtime/monitor.cc
+++ b/runtime/monitor.cc
@@ -457,7 +457,7 @@
   if (!Runtime::Current()->IsStarted() || VLOG_IS_ON(monitor)) {
     std::ostringstream ss;
     self->Dump(ss);
-    LOG(Runtime::Current()->IsStarted() ? INFO : ERROR)
+    LOG(Runtime::Current()->IsStarted() ? ::android::base::INFO : ::android::base::ERROR)
         << self->GetException()->Dump() << "\n" << ss.str();
   }
   va_end(args);