Demangle gcc names for foreign libs

[iarkhanhelsky]

Add post processing for unpacked traces and demangle C++ ABI identifiers:

_ZN10A5xContext20WriteTexSamplersRegsEPjii

should be converted to

A5xContext::WriteTexSamplersRegs(unsigned int*, int, int)

[iarkhanhelsky]

C++ names mangling rules
https://itanium-cxx-abi.github.io/cxx-abi/abi.html#mangling