[llvm] [PowerPC] Support local-dynamic TLS relocation on AIX (PR #66316)

[Amy Kwan via llvm-commits]

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@@ -1584,12 +1584,19 @@ def GETtlsldADDRPCREL : GETtlsldADDRPseudo <"#GETtlsldADDRPCREL">;
 // so we don't need to mark it with a size of 8 bytes. Finally, the assembly
 // manual mentions this exact set of registers as the clobbered set, others
 // are guaranteed not to be clobbered.
-let Defs = [X0,X4,X5,X11,LR8,CR0] in
+let Defs = [X0,X4,X5,X11,LR8,CR0] in {
 def GETtlsADDR64AIX :
   PPCEmitTimePseudo<(outs g8rc:$rD),(ins g8rc:$offset, g8rc:$handle),
                     "GETtlsADDR64AIX",
                     [(set i64:$rD,
                       (PPCgetTlsAddr i64:$offset, i64:$handle))]>, isPPC64;
+// On AIX, the call to .__tls_get_mod need one input in X3 for the module handle.
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amy-kwan wrote:

```suggestion
// On AIX, the call to .__tls_get_mod needs one input in X3 for the module handle.
```

https://github.com/llvm/llvm-project/pull/66316