PR middle-end/78786 - GCC hangs/out of memory calling sprintf with large precision

gcc/ChangeLog:

	PR middle-end/78786
	* gimple-ssa-sprintf.c (target_dir_max): New macro.
	(get_mpfr_format_length): New function.
	(format_integer): Use HOST_WIDE_INT instead of int.
	(format_floating_max): Same.
	(format_floating): Call get_mpfr_format_length.
	(format_directive): Use target_dir_max.

gcc/testsuite/ChangeLog:

	PR middle-end/78786
	* gcc.dg/tree-ssa/builtin-sprintf-warn-7.c: New test.

From-SVN: r243672