[tests] restore ./tests from master

tests/float/oracle_equalities/nonlin.1.res.oracle

tests/float/oracle_equalities/nonlin.2.res.oracle

tests/float/oracle_equalities/nonlin.4.res.oracle

tests/float/oracle_equalities/nonlin.5.res.oracle

tests/float/oracle_equalities/parse.res.oracle

tests/float/special_floats.c

tests/idct/diff_equalities

tests/idct/diff_gauges

tests/idct/diff_octagons

tests/idct/oracle_equalities/ieee_1180_1990.res.oracle

tests/jcdb/jcdb.c

tests/jcdb/oracle/list_files.err

tests/journal/intra.ml

tests/journal/oracle/control2_sav.err

tests/libc/check_parsing_individual_headers.ml

tests/libc/oracle/math_h.res.oracle

tests/libc/test_config_gcc

tests/metrics/used-files.i

tests/misc/array_size_specifier_unification.i

tests/misc/bts0451.i