re PR tree-optimization/93098 (ICE with negative shifter)

re PR tree-optimization/93098 (ICE with negative shifter)

	PR tree-optimization/93098
	* match.pd (popcount): For shift amounts, use integer_onep
	or wi::to_widest () == cst instead of tree_to_uhwi () == cst
	tests.  Make sure that precision is power of two larger than or equal
	to 16.  Ensure shift is never negative.  Use HOST_WIDE_INT_UC macro
	instead of ULL suffixed constants.  Formatting fixes.

	* gcc.c-torture/compile/pr93098.c: New test.

From-SVN: r279809