[E-ACSL] improve handling of typing context

src/plugins/e-acsl/TODO

src/plugins/e-acsl/doc/Changelog

src/plugins/e-acsl/env.ml

src/plugins/e-acsl/env.mli

src/plugins/e-acsl/tests/e-acsl-runtime/loop.i

...s/e-acsl/tests/e-acsl-runtime/oracle/bts1324.1.res.oracle

...ins/e-acsl/tests/e-acsl-runtime/oracle/bts1390.res.oracle

...ins/e-acsl/tests/e-acsl-runtime/oracle/bts1399.res.oracle

...lugins/e-acsl/tests/e-acsl-runtime/oracle/cast.res.oracle

src/plugins/e-acsl/tests/e-acsl-runtime/oracle/gen_bts1326.c

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

...sl/tests/e-acsl-runtime/oracle/linear_search.1.res.oracle

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

...lugins/e-acsl/tests/e-acsl-runtime/oracle/loop.res.oracle

...ugins/e-acsl/tests/e-acsl-runtime/oracle/ptr.1.res.oracle

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

src/plugins/e-acsl/translate.ml

src/plugins/e-acsl/typing.ml

src/plugins/e-acsl/typing.mli