ELF2: Initialize SyntheticOptional only once.

llvm-svn: 249636
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index c31656d..8641bba 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -147,6 +147,8 @@
 }
 
 void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
+  initSymbols();
+
   // Parse command line options.
   opt::InputArgList Args = Parser.parse(ArgsArr);