[ORC] Convert null remote symbols to null JITSymbols.

The existing code created a JITSymbol with an invalid materializer instead,
guaranteeing a 'missing symbol' error when someone tried to materialize the
symbol.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312584 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed