Implement --export-dynamic.

llvm-svn: 248347
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index 6537e13..9d487ad 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -88,6 +88,9 @@
   if (Args.hasArg(OPT_discard_locals))
     Config->DiscardLocals = true;
 
+  if (Args.hasArg(OPT_export_dynamic))
+    Config->ExportDynamic = true;
+
   // Create a list of input files.
   std::vector<MemoryBufferRef> Inputs;