[lld] [lld][ELF] Add basic TLSDESC support for LoongArch (PR #94451)

[WÁNG Xuěruì via llvm-commits]

================
@@ -1303,6 +1303,19 @@ static unsigned handleTlsRelocation(RelType type, Symbol &sym,
 
   if (config->emachine == EM_MIPS)
     return handleMipsTlsRelocation(type, sym, c, offset, addend, expr);
+
+  // LoongArch does not yet implemented TLSDESC transition of DESC to LE/IE.
+  // Generates TLSDESC dynamic relocation for the symbol that is handled by the
+  // dynamic linker.
----------------
xen0n wrote:

```suggestion
  // LoongArch does not yet implement transition from TLS DESC to LE/IE, so
  // generate TLSDESC dynamic relocation for the dynamic linker to handle.
```

https://github.com/llvm/llvm-project/pull/94451