Strange number of references to a mapping.
Imported from https://youtrack.roxen.com/issue/PIKE-30
Reported by @grubba
Blocking PIKE-20
Doing tests in testsuite (11914 tests, pid 12730)
**Block: 0xd0f0ded0c0 Type: mapping Refs: -253832321
*******************
/home/hungerf3/xeno/xenoclient/[pike-8](#8008).1/cruncher.ofdoom.com/buildtmp/Pike-v8.1-snapshot/src/mapping.c:67: Fatal error:
really free mapping on mapping with -253832321 refs.
No stack - no backtrace.
Aborted (core dumped)
Testing vtables and scope access: 8:19264
/home/hungerf3/xeno/xenoclient/[pike-8](#8008).1/cruncher.ofdoom.com/buildtmp/Pike-v8.1-snapshot/src/testsuite.in:5643: Test 1000 (shift 1) (CRNL) failed.
1: mixed a() {
2: Stdio.write_file ("testsuite_test.pike", #"\
3: int main()
4: {
5: Thread.Mutex m = Thread.Mutex();
6: Thread.MutexKey l = m->lock();
7: Thread.thread_create (lambda () {m->lock(); exit (0);});
8: call_out (destruct, 0, l);
9: return -1;
10: }");
11: return Process.system (RUNPIKE +" testsuite_test.pike");
12: ; }
13: mixed b() { return 0; }
o->a(): 134
o->b(): 0