[flang][test] Adjust Driver/pass-plugin-not-found.f90 error message

[ro]

Summary

The Driver/pass-plugin-not-found.f90 test FAILs on Solaris since part of the error message differs from what the test expects: Solaris has

error: unable to load plugin 'X.Y': 'Could not load library 'X.Y': ld.so.1: flang-new: X.Y: open failed: No such file or directory'

while the test expects

error: unable to load plugin 'X.Y': 'Could not load library 'X.Y': X.Y: cannot open shared object file: No such file or directory'

The last part is emitted by the system dlerror and is thus unportable. Hopefully the error test itself is the same everywhere.

The following patch adjusts the expected message accordingly.

Tested on x86_64-pc-linux-gnu and amd64-pc-solaris2.11.

[awarzynski]

Thanks a ton for doing this, LGTM!

flang/test/Driver/pass-plugin-not-found.f90

 ! Check the correct error diagnostic is reported when a pass plugin shared object isn't found
 
 ! REQUIRES: plugins, shell
 
 ! RUN: not %flang -fpass-plugin=X.Y %s 2>&1 | FileCheck %s --check-prefix=ERROR
 ! RUN: not %flang_fc1 -emit-llvm -o /dev/null -fpass-plugin=X.Y %s 2>&1 | FileCheck %s --check-prefix=ERROR
 
-! ERROR: error: unable to load plugin 'X.Y': 'Could not load library 'X.Y': X.Y: cannot open shared object file: No such file or directory'
+! The exact wording of the error message depends on the system dlerror.
+! ERROR: error: unable to load plugin 'X.Y': 'Could not load library 'X.Y': {{.*}}: No such file or directory'