Mangled symbols in stack traces

When using JUCE_HEAVYWEIGHT_LEAK_DETECTOR (which is great btw!), I get mangled symbol names that are not so readable and may as well be in Hebrew :wink:

The following patch turns them into proper C++ symbol names that we recognize, on macOS (tested) and also in Linux: Demangle stack traces in macOS/Linux · soundradix/JUCE@b39dd02 · GitHub

Based on a gist by fmela but JUCEified