RFR(S) 8176887: SIGSEGV in AOTCodeHeap::next when using specific configuration

[Igor Veresov]

The problem here is that AOTCodeHeap::got_metadata_do() iterates over the _metaspace_got array assuming that the array contains Metadata*, indeed the array is declared as such. However it also happens to contain MethodCounters*, and MethodCounters is not Metadata, but MetaspaceObj. The simplest and minimal risk solution is to make MethodCounters a subclass of Metadata (we’d like to have this fix in jdk9).


Webrev: http://cr.openjdk.java.net/~iveresov/8176887/webrev.00/ 
JBS: https://bugs.openjdk.java.net/browse/JDK-8176887

Thanks!
igor