[tests] update wrt support of literal strings

src/plugins/e-acsl/tests/bts/oracle/bts1390.res.oracle

src/plugins/e-acsl/tests/bts/oracle/bts1398.res.oracle

src/plugins/e-acsl/tests/bts/oracle/bts1837.1.res.oracle

src/plugins/e-acsl/tests/bts/oracle/bts1837.err.oracle

src/plugins/e-acsl/tests/bts/oracle/bts1837.res.oracle

src/plugins/e-acsl/tests/bts/oracle/gen_bts1837.c

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

src/plugins/e-acsl/tests/e-acsl-runtime/oracle/gen_stdout2.c

...ns/e-acsl/tests/e-acsl-runtime/oracle/stdout.1.res.oracle

...gins/e-acsl/tests/e-acsl-runtime/oracle/stdout.res.oracle