Revert "Add support for thread-local storage variables"

TLS support in tinyCC is absolutely not ready:
- segment register not select in load and store
- no relocation added for computing offset of per-thread symbol
- no support for TLS-specific relocations
- no program header added as per Drepper document about TLS

This reverts commit 1c4afd1350.

libtcc.c

@@ -444,10 +444,7 @@ ST_FUNC void put_extern_sym2(Sym *sym, Section *section,
     } else if ((sym->type.t & VT_BTYPE) == VT_VOID) {
         sym_type = STT_NOTYPE;
     } else {
-        if (section && section->sh_flags & SHF_TLS)
-            sym_type = STT_TLS;
-        else
-            sym_type = STT_OBJECT;
+        sym_type = STT_OBJECT;
     }
 
     if (sym->type.t & VT_STATIC)