[e-acsl] new option -e-acsl-gmp-only: used in tests to check the GMP translation

src/plugins/e-acsl/tests/e-acsl-runtime/oracle/gen_ptr.c

src/plugins/e-acsl/tests/e-acsl-runtime/oracle/gen_ptr2.c

src/plugins/e-acsl/tests/e-acsl-runtime/oracle/gen_quantif.c

...plugins/e-acsl/tests/e-acsl-runtime/oracle/gen_quantif2.c

src/plugins/e-acsl/tests/e-acsl-runtime/oracle/gen_result.c

src/plugins/e-acsl/tests/e-acsl-runtime/oracle/gen_result2.c

src/plugins/e-acsl/tests/e-acsl-runtime/oracle/gen_sizeof.c

src/plugins/e-acsl/tests/e-acsl-runtime/oracle/gen_sizeof2.c

...ns/e-acsl/tests/e-acsl-runtime/oracle/gen_stmt_contract.c

...s/e-acsl/tests/e-acsl-runtime/oracle/gen_stmt_contract2.c

src/plugins/e-acsl/tests/e-acsl-runtime/oracle/gen_true.c

src/plugins/e-acsl/tests/e-acsl-runtime/oracle/gen_true2.c

src/plugins/e-acsl/tests/e-acsl-runtime/oracle/gen_typedef.c

...plugins/e-acsl/tests/e-acsl-runtime/oracle/gen_typedef2.c

...tests/e-acsl-runtime/oracle/integer_constant.1.err.oracle

...tests/e-acsl-runtime/oracle/integer_constant.1.res.oracle

...l/tests/e-acsl-runtime/oracle/integer_constant.res.oracle

...e-acsl/tests/e-acsl-runtime/oracle/invariant.1.err.oracle

...e-acsl/tests/e-acsl-runtime/oracle/invariant.1.res.oracle

...s/e-acsl/tests/e-acsl-runtime/oracle/invariant.res.oracle