x86_32 fails with -XX:+VerifyGraphEdges after JDK-8293979

```
$ CONF=linux-x86-server-fastdebug make images test TEST=compiler/c2/TestVerifyGraphEdges.java

...

TEST RESULT: Failed. Unexpected exit from test [exit code: 139]
```

It produces no hs_err, must be crashing somewhere outside the usual error handler reach.

The easier way to reproduce is:

```
$ build/linux-x86-server-fastdebug/images/jdk/bin/java -Xshare:on -Xbatch -Xcomp -XX:+VerifyGraphEdges
```

Doing `-Xshare:off` passes. Doing `-XX:-VerifyGraphEdges` passes.

Bisection points to JDK-8293979, so I am presuming this is a runtime, not compiler bug.