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

[Amy Kwan via llvm-commits]

================
@@ -370,11 +370,23 @@ namespace llvm {
     /// G8RC = TLSGD_AIX, TOC_ENTRY, TOC_ENTRY
     /// Op that combines two register copies of TOC entries
     /// (region handle into R3 and variable offset into R4) followed by a
-    /// GET_TLS_ADDR node which will be expanded to a call to __get_tls_addr.
+    /// GET_TLS_ADDR node which will be expanded to a call to .__tls_get_addr.
     /// This node is used in 64-bit mode as well (in which case the result is
     /// G8RC and inputs are X3/X4).
     TLSGD_AIX,
 
+    /// %x3 = GET_TLS_MOD_AIX _$TLSML - For the AIX local-dynamic TLS model,
+    /// produces a call to .__tls_get_mod(_$TLSML\@ml).
+    GET_TLS_MOD_AIX,
+
+    /// [GP|G8]RC = TLSLD_AIX, TOC_ENTRY(variable offset)
+    /// Op that internally creates TOC entry for the "_$TLSML" symbol, generates
+    /// GET_TLS_MOD_AIX node which will be expanded into a call to
+    /// .__tls_get_mod, and then add the variable offset with the result from
----------------
amy-kwan wrote:

```suggestion
    /// .__tls_get_mod, and then adds the variable offset with the result from
```

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