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

[Felix via cfe-commits]

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@@ -649,6 +649,14 @@ void XCOFFObjectWriter::recordRelocation(MCAssembler &Asm,
                                          uint64_t &FixedValue) {
   auto getIndex = [this](const MCSymbol *Sym,
                          const MCSectionXCOFF *ContainingCsect) {
+    // Fixup relocation flag for AIX TLS local-dynamic mode.
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orcguru wrote:

Proposed to fix the setting for the "_$TLSML" symbol in `TargetLoweringObjectFileXCOFF::getSectionForExternalReference()`.

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