[lld] [LLD][COFF] Add -build-id flag to generate .buildid section. (PR #71433)

[Zequan Wu via llvm-commits]

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@@ -196,6 +196,9 @@ defm guard_longjmp : B<"guard-longjmp",
   "Do not enable Control Flow Guard long jump hardening">;
 defm error_limit:
   EqLong<"error-limit", "Maximum number of errors to emit before stopping (0 = no limit)">;
+def build_id: J<"build-id=">, HelpText<"Generate build ID note (pass none to disable)">, 
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ZequanWu wrote:

This is to be consistent with elf's build-id options, though it doesn't matter. The error message "unsupported build id hashing: {} using default hashing." is more user friendly than unknown flags if we handle it inside driver.

https://github.com/llvm/llvm-project/pull/71433