Symbolization

[Arthur Eubanks]

It looks like the libtsan.so from gcc 8 is out of date. It doesn't
contain __tsan_symbolize_external_ex(), only the
legacy __tsan_symbolize_external(). This messes with testing the Java Tsan
patches.

$ strings /usr/lib/gcc/x86_64-linux-gnu/8/libtsan.so | grep __tsan_sym

I looked at the latest gcc sources and it does have a version of Tsan that
includes __tsan_symbolize_external_ex(). We could tell people to compile
their own gcc and use that libtsan.so.
$ apt search gcc
only shows up to gcc 8 on my machine.

Thoughts?