Crash in add_jar on raspbian/armhf

[Tak]

I was trying to run an external project, but it also occurs with the rjb test suite.
It looks very similar to #80 , but I have only ever had one jdk here.

I've tried a couple of the usual suspects, like -mlong-calls and -Wl,-Bsymbolic, with no luck.
I'm happy to debug / try source modifications, but I don't have a good lead at this point.

Linux raspberrypi 5.4.51-v7l+ #1327 SMP Thu Jul 23 11:04:39 BST 2020 armv7l GNU/Linux

ruby 2.6.6p146 (2020-03-31 revision 67876) [armv7l-linux-eabihf]

openjdk version "11.0.12" 2021-07-20
OpenJDK Runtime Environment (build 11.0.12+7-post-Raspbian-2deb10u1)
OpenJDK Server VM (build 11.0.12+7-post-Raspbian-2deb10u1, mixed mode)

output.log
Makefile.txt
mkmf.log

[Tak]

Ok, it's related to varargs forwarding in NewObject/CallObjectMethod - if I replace these with calls to NewObjectA/CallObjectMethodA, everything is happy.
It's unclear to me right now whether this is a usage bug in rjb relying on undefined behavior, an openjdk bug, or missing compiler flags.