* and #pragma pop_macro("macro_name")

* give warning if pragma is unknown for tcc
    * don't free asm_label in sym_free(),
      it's a job of the asm_free_labels().

    The above pragmas are used in the mingw headers.
    Thise pragmas are implemented in gcc-4.5+ and current
    clang.

tccgen.c

@@ -152,7 +152,6 @@ static inline Sym *sym_malloc(void)
 ST_INLN void sym_free(Sym *sym)
 {
     sym->next = sym_free_first;
-    tcc_free(sym->asm_label);
     sym_free_first = sym;
 }