[tests] refactoring of pdg tests

Makefile

tests/pdg/annot.c

tests/pdg/array_struct.i

tests/pdg/assigns.i

tests/pdg/bts1194.c

tests/pdg/call.c

tests/pdg/calls_and_implicits.c

tests/pdg/const.i

tests/pdg/decl_dpds.c

tests/pdg/doc_dot.c

tests/pdg/dpds_intra.c

tests/pdg/dyn_dpds.c

tests/pdg/globals.c

tests/pdg/inter_alias2.c

tests/pdg/loops.c

tests/pdg/multiple_calls.c

tests/pdg/no_body.c

tests/pdg/oracle/const.res.oracle

tests/pdg/pb_infinite_loop.c

tests/pdg/postdom.c