* builtins.c (fold_builtin_cosh): New.
	(fold_builtin_1): Use it.
	* fold-const.c (negate_mathfn_p): Add llround, lround, round,
	trunc to the list of "odd" functions.  Also add llrint, lrint,
	rint and nearbyint when flag_rounding_math is false.

testsuite:
	* gcc.dg/torture/builtin-symmetric-1.c: Add more cases.

From-SVN: r118733