[ELF] - Add test to check we don't crash when tracing reserved symbol.
[ELF] - Add test to check we don't crash when tracing reserved symbol.

This is to test the following line of code:
https://github.com/llvm-mirror/lld/blob/master/ELF/SymbolTable.cpp#L601

Without that line linker would crash.

git-svn-id: f6089bf0e6284f307027cef4f64114ee9ebb0424@336345 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/lld,llvm-mirror/lld