build: cause the "check" rule to depend on $(PROGRAMS)
Summary:
* Makefile (check): Cause "make check" to build all $(PROGRAMS),
so that it verifies that the few benchmark-only source files that
not already built via "make check" do compile and link successfully.
Test Plan:
run "make clean; make check", and verify that
table/table_reader_bench.cc is now compiled.
Before, it was not, which led to an incomplete fix
for a build break.