[llvm] [llvm-symbolizer] Recognize AIX big archive (PR #150401)

[James Henderson via llvm-commits]

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@@ -535,16 +535,20 @@ MACH-O SPECIFIC OPTIONS
 .. option:: --default-arch <arch>
 
   If a binary contains object files for multiple architectures (e.g. it is a
-  Mach-O universal binary), symbolize the object file for a given architecture.
-  You can also specify the architecture by writing ``binary_name:arch_name`` in
-  the input (see example below). If the architecture is not specified in either
-  way, the address will not be symbolized. Defaults to empty string.
+  Mach-O universal binary or an AIX archive with architecture variants),
+  symbolize the object file for a given architecture. You can also specify
+  the architecture by writing ``binary_name:arch_name`` in the input (see
+  example below). For AIX archives, the format ``archive.a(member.o):arch``
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jh7370 wrote:

It's not: you can add two members to the same GNU format archive using `q`. It would be a little unusual doing so, but it's doable and if the members' public symbols didn't overlap, it could even be used for linking successfully without special options or needing to be on AIX, for example.

https://github.com/llvm/llvm-project/pull/150401