Fallback to the default stringize function to show some meaningful error message.
Fallback to the default stringize function to show some meaningful error message.

GNU LD driver only understood no_such_file_or_directory error and was showing
just "Unknown Error" for any other type of error. With this patch, the driver
now prints file name and error message string by default.

git-svn-id: f6089bf0e6284f307027cef4f64114ee9ebb0424@191070 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/lld,llvm-mirror/lld