[llvm] [symbolizer] Empty string is not an error (PR #92660)

[James Henderson via llvm-commits]

================
@@ -1,9 +1,9 @@
 # If binary input file is not specified, llvm-symbolizer assumes it is the first
 # item in the command.
 
-# No input items at all, complain about missing input file.
+# No input items at all. Report unknown line, but do not produce any output on stderr.
----------------
jh7370 wrote:

```suggestion
# No input items at all. Report an unknown line, but do not produce any output on stderr.
```

https://github.com/llvm/llvm-project/pull/92660