ART: Add support for runtime debug checks

Add support for runtime-switchable debug flags. These flags are only
enabled in debug mode, and a constexpr false in release mode. This
allows to distinguish fast from slow checks, for example.

To simplify usage, two macros should be used. DECLARE_RUNTIME_DEBUG_FLAG
defines a static class member or constexpr as the flag. DEFINE_RUNTIME_DEBUG_FLAG
defines the static storage and registers it, if needed. See the
documentation in logging.h.

As is, runtime checks are disabled by default. Pass -XX:SlowDebug=true
to enable them on startup.

Add logging_test. Fix up tests and scripts to enable slow debug checks.

Bug: 35644369
Test: m test-art-host
Change-Id: Icc1cb0bb921d863514c55abef794c5c96f8af801
diff --git a/runtime/runtime_options.def b/runtime/runtime_options.def
index cfc681f..3d23e20 100644
--- a/runtime/runtime_options.def
+++ b/runtime/runtime_options.def
@@ -142,4 +142,6 @@
                                                                           // Runtime::Abort.
 RUNTIME_OPTIONS_KEY (void (*)(),          HookAbort,                      nullptr)
 
+RUNTIME_OPTIONS_KEY (bool,                SlowDebug,                      false)
+
 #undef RUNTIME_OPTIONS_KEY