PG11 jit failing on ppc64el

PG 11 beta1 is failing on ppc64el. All Debian/Ubuntu releases except
Jessie are affected. My guess is on problems with llvm/jit, because of
the C++ style error message (and LLVM is disabled on Jessie).

Debian sid:
15:59:29 2018-05-22 13:59:24.914 UTC [29081] pg_regress/strings STATEMENT: SELECT chr(0);
15:59:29 terminate called after throwing an instance of 'std::bad_function_call'
15:59:29 what(): bad_function_call
15:59:29 2018-05-22 13:59:25.026 UTC [28961] LOG: server process (PID 29085) was terminated by signal 6: Aborted
15:59:29 2018-05-22 13:59:25.026 UTC [28961] DETAIL: Failed process was running: INSERT INTO TEMP_GROUP
15:59:29 SELECT 1, (- i.f1), (- f.f1)
15:59:29 FROM INT4_TBL i, FLOAT8_TBL f;
15:59:29 2018-05-22 13:59:25.026 UTC [28961] LOG: terminating any other active server processes
15:59:29 2018-05-22 13:59:25.026 UTC [29078] WARNING: terminating connection because of crash of another server process

Debian stretch:
15:58:45 2018-05-22 13:58:43.778 UTC [29981] pg_regress/indexing STATEMENT: insert into fastpath values (1, 'b1', 100.00);
15:58:45 terminate called after throwing an instance of 'std::bad_function_call'
15:58:45 what(): bad_function_call
15:58:45 2018-05-22 13:58:43.975 UTC [28908] LOG: server process (PID 29981) was terminated by signal 6: Aborted
15:58:45 2018-05-22 13:58:43.975 UTC [28908] DETAIL: Failed process was running: select md5(string_agg(a::text, b order by a, b asc)) from fastpath
15:58:45 where a >= 1000 and a < 2000 and b > 'b1' and b < 'b3';
15:58:45 2018-05-22 13:58:43.975 UTC [28908] LOG: terminating any other active server processes
15:58:45 2018-05-22 13:58:43.975 UTC [30037] WARNING: terminating connection because of crash of another server process

Christoph