Try to fix the build on windows.

llvm-svn: 193431
diff --git a/llvm/unittests/Support/Path.cpp b/llvm/unittests/Support/Path.cpp
index cc8731b..070fb64 100644
--- a/llvm/unittests/Support/Path.cpp
+++ b/llvm/unittests/Support/Path.cpp
@@ -461,7 +461,7 @@
   }
   {
     OwningPtr<MemoryBuffer> Buf;
-    MemoryBuffer::getFile(FilePathname, Buf);
+    MemoryBuffer::getFile(FilePathname.c_str(), Buf);
     EXPECT_EQ(Buf->getBuffer(), "\r\n");
   }
 
@@ -472,7 +472,7 @@
   }
   {
     OwningPtr<MemoryBuffer> Buf;
-    MemoryBuffer::getFile(FilePathname, Buf);
+    MemoryBuffer::getFile(FilePathname.c_str(), Buf);
     EXPECT_EQ(Buf->getBuffer(), "\n");
   }
 }