testsuite: popcount[45]ll require lp64

testsuite: popcount[45]ll require lp64

popcount[45]ll require __builtin_popcountll, but the test can succeed
without libcall through expand_doubleword_popcount.  However the Tree-SSA
optiization requires recognition of POPCOUNT.  This patch limits the test
to lp64 for the targets that fall through the cracks and were not
caught by the dg-require-effective-target popcountll.

gcc/testsuite/ChangeLog

2020-06-19  David Edelsohn  <dje.gcc@gmail.com>

	* gcc.dg/tree-ssa/popcount4ll.c: Add target lp64.
	* gcc.dg/tree-ssa/popcount5ll.c: Same.