Remove useless cpp files

Author: tautschnig

src/solvers/Makefile

@@ -186,7 +186,6 @@ SRC = $(BOOLEFORCE_SRC) \
       sat/dimacs_cnf.cpp \
       sat/pbs_dimacs_cnf.cpp \
       sat/resolution_proof.cpp \
-      sat/satcheck.cpp \
       smt2/smt2_conv.cpp \
       smt2/smt2_dec.cpp \
       smt2/smt2_parser.cpp \

src/solvers/sat/satcheck.cpp

@@ -24,7 +24,6 @@ SRC = arith_tools.cpp \
       fresh_symbol.cpp \
       get_base_name.cpp \
       get_module.cpp \
-      graph.cpp \
       guard.cpp \
       identifier.cpp \
       ieee_float.cpp \