[tests] moving GMP-specific test files

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

...s/e-acsl/tests/e-acsl-runtime/oracle/quantif.0.res.oracle

src/plugins/e-acsl/tests/gmp/arith.i

src/plugins/e-acsl/tests/gmp/array.i

src/plugins/e-acsl/tests/gmp/at.i

src/plugins/e-acsl/tests/gmp/cast.i

src/plugins/e-acsl/tests/gmp/comparison.i

src/plugins/e-acsl/tests/gmp/integer_constant.i

src/plugins/e-acsl/tests/gmp/longlong.i

src/plugins/e-acsl/tests/gmp/not.i

src/plugins/e-acsl/tests/gmp/oracle/arith.0.err.oracle

src/plugins/e-acsl/tests/gmp/oracle/arith.0.res.oracle

src/plugins/e-acsl/tests/gmp/oracle/arith.1.err.oracle

src/plugins/e-acsl/tests/gmp/oracle/arith.1.res.oracle

src/plugins/e-acsl/tests/gmp/oracle/array.0.err.oracle

src/plugins/e-acsl/tests/gmp/oracle/array.0.res.oracle

src/plugins/e-acsl/tests/gmp/oracle/array.1.err.oracle

src/plugins/e-acsl/tests/gmp/oracle/array.1.res.oracle

src/plugins/e-acsl/tests/gmp/oracle/at.0.err.oracle

src/plugins/e-acsl/tests/gmp/oracle/at.0.res.oracle