re PR target/29776 (result of ffs/clz/ctz/popcount/parity are already sign-extended)

	PR target/29776
	* fold-const.c (tree_call_nonnegative_warnv_p): Return true
	for BUILT_IN_C{LZ,LRSB}*.
	* tree.h (CASE_INT_FN): Add FN##IMAX case.
	* tree-vrp.c (extract_range_basic): Handle
	BUILT_IN_{FFS,PARITY,POPCOUNT,C{LZ,TZ,LRSB}}*.  For
	BUILT_IN_CONSTANT_P if argument isn't (D) of PARM_DECL,
	fall thru to code calling set_value*.
	* builtins.c (expand_builtin): Remove *IMAX cases.
	(fold_builtin_bitop): For BUILT_IN_CLRSB* return NULL_TREE
	if width is bigger than 2*HWI.

	* libgcc2.c (__floattisf): Avoid undefined signed overflow.

	* gcc.dg/tree-ssa/vrp89.c: New test.

From-SVN: r200731