Another attempt at fixing the bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184318 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-ar/llvm-ar.cpp b/tools/llvm-ar/llvm-ar.cpp
index 9dacbde..27df8d8 100644
--- a/tools/llvm-ar/llvm-ar.cpp
+++ b/tools/llvm-ar/llvm-ar.cpp
@@ -430,7 +430,7 @@
       // Open up a file stream for writing
       std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
                                    std::ios::binary;
-      std::ofstream file(I->getPath().str(), io_mode);
+      std::ofstream file(I->getPath().str().c_str(), io_mode);
 
       // Get the data and its length
       const char* data = reinterpret_cast<const char*>(I->getData());