[llvm] [z/OS] Modify regex in error message to match on z/OS. (PR #194020)

[James Henderson via llvm-commits]

================
@@ -18,7 +18,7 @@
 # CHECK: Command Output (stderr):
 # CHECK-NEXT: --
 # CHECK-NOT: --
-# CHECK: cat{{(_64)?(\.exe)?}}: {{(cannot open does-not-exist|.*does-not-exist.*: No such file or directory)}}
+# CHECK: cat{{(_64)?(\.exe)?}}: {{(cannot open does-not-exist|.*does-not-exist.*: .*No such file or directory)}}
----------------
jh7370 wrote:

You could move the regex to the FileCheck invocation and put the whole thing inside the variable, e.g.
```
# RUN: FileCheck < %t.out %s -DPATTERN={{(cannot open does-not-exist|.*does-not-exist.*: %errc_ENOENT)}}

# CHECK: cat{{(_64)?(\.exe)?}}: [[PATTERN]]
```

https://github.com/llvm/llvm-project/pull/194020