tree-tailcall.c (tree_optimize_tail_calls_1): Use fold_convert, reverting my 2004-09-07 patch to use build_int_cst.

.:	* tree-tailcall.c (tree_optimize_tail_calls_1): Use fold_convert,
	reverting my 2004-09-07 patch to use build_int_cst.
testsuite:
	* gcc.c-torture/compile/acc1.c: New.

From-SVN: r88759