[llvm] [DirectX] Add `extract-section` to `llvm-objcopy` and implement it for `DXContainer` (PR #154804)

[James Henderson via llvm-commits]

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@@ -28,6 +52,15 @@ static Error handleArgs(const CommonConfig &Config, Object &Obj) {
       return Config.ToRemove.matches(P.Name);
     };
 
+  for (StringRef Flag : Config.ExtractSection) {
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jh7370 wrote:

Since this has no impact on the section removal stuff, I'd move it to the start of the function.

https://github.com/llvm/llvm-project/pull/154804