8204164: OOM-only logging in Metaspace

Reviewed-by: gziemski, coleenp

src/hotspot/share/logging/logTag.hpp

@@ -103,6 +103,7 @@
   LOG_TAG(normalize) \
   LOG_TAG(objecttagging) \
   LOG_TAG(obsolete) \
+  LOG_TAG(oom) \
   LOG_TAG(oopmap) \
   LOG_TAG(oopstorage) \
   LOG_TAG(os) \

src/hotspot/share/memory/metaspace.cpp

@@ -1270,7 +1270,7 @@ void Metaspace::report_metadata_oome(ClassLoaderData* loader_data, size_t word_s
   tracer()->report_metadata_oom(loader_data, word_size, type, mdtype);
 
   // If result is still null, we are out of memory.
-  Log(gc, metaspace, freelist) log;
+  Log(gc, metaspace, freelist, oom) log;
   if (log.is_info()) {
     log.info("Metaspace (%s) allocation failed for size " SIZE_FORMAT,
              is_class_space_allocation(mdtype) ? "class" : "data", word_size);