[gold] Remove inconsistent llvm_unreachable().

Differential Revision:	 http://reviews.llvm.org/D16429

llvm-svn: 258561

llvm/tools/gold/gold-plugin.cpp

@@ -344,7 +344,6 @@ static void diagnosticHandler(const DiagnosticInfo &DI) {
   case DS_Error:
     message(LDPL_FATAL, "LLVM gold plugin has failed to create LTO module: %s",
             ErrStorage.c_str());
-    llvm_unreachable("Fatal doesn't return.");
   case DS_Warning:
     Level = LDPL_WARNING;
     break;