Bug#913271: segfault - broken rust compiling

[Josh Stone]

There's an ABI incompatibility between LLVM compiled with GCC and Clang:
https://bugs.llvm.org/show_bug.cgi?id=39427

So if you have a Clang-built libLLVM.so, and rustc's src/rustllvm is
built with GCC, then I think you may be hitting this problem.