[llvm] [objcopy] Return an error in case of an invalid regex (PR #74319)

[James Henderson via llvm-commits]

================
@@ -39,16 +39,15 @@ NameOrPattern::create(StringRef Pattern, MatchStyle MS,
                          IsPositiveMatch);
   }
   case MatchStyle::Regex: {
-    SmallVector<char, 32> Data;
-    auto AnchoredPattern =
-        ("^" + Pattern.ltrim('^').rtrim('$') + "$").toStringRef(Data);
-    auto RegEx = std::make_shared<Regex>(AnchoredPattern);
+    auto RegEx = Regex(Pattern);
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jh7370 wrote:

```suggestion
    Regex RegEx(Pattern);
```

https://github.com/llvm/llvm-project/pull/74319