[llvm] [llvm-strip] Let llvm-strip continue on encountering an error (PR #129531)

[James Henderson via llvm-commits]

================
@@ -0,0 +1,23 @@
+## Checks that llvm-strip continues to strip objects after encountering a bad
+## one while emitting an error for each bad one.
+
+# RUN: echo "bad" > %t1
+# RUN: yaml2obj %s -o %t2
+# RUN: not llvm-strip %t1 %t2 2>&1 | FileCheck %s --check-prefix=ERROR
+
+# ERROR: error: {{.*}}: The file was not recognized as a valid object file
----------------
jh7370 wrote:

This testing only shows that an error is seen for the first bad input and not for subsequent ones. To check that all errors are emitted, I suggest something like the below. I also suggest trying to match the file names and to show that you only had the expected errors (FileCheck will ignore text it isn't interested in, not fail unless told otherwise). I've provided a syntax that leverages FileCheck's -D option to achieve this, but you might need to tweak it to actually make it work.
```
# RUN: cp %t1 %t3
# RUN: not llvm-strip %t1 %t2 %t3 2>&1 | FileCheck %s --check-prefix=ERROR -DFILE1=%t1 -DFILE3=%t3 --implicit-check-not=error:

# ERROR: error: [[FILE1]]: The file was not recognized as a valid object file
# ERROR-NEXT: error: [[FILE3]]: The file was not recognized as a valid object file
```

https://github.com/llvm/llvm-project/pull/129531