[parser] yet more improved locations in the AST.

src/kernel_internals/parsing/clexer.mll

src/kernel_internals/parsing/cparser.mly

tests/syntax/oracle/empty_base.0.res.oracle

tests/syntax/oracle/empty_base.1.res.oracle

tests/syntax/oracle/generic.1.res.oracle

tests/syntax/oracle/generic.8.res.oracle

tests/syntax/oracle/ghost_cv_parsing_errors.0.res.oracle

tests/syntax/oracle/ghost_cv_parsing_errors.1.res.oracle

tests/syntax/oracle/ghost_cv_parsing_errors.2.res.oracle

tests/syntax/oracle/ghost_else_bad.2.res.oracle

tests/syntax/oracle/ghost_else_bad_oneline.res.oracle

tests/syntax/oracle/ghost_multiline_annot.2.res.oracle

tests/syntax/oracle/ghost_multiline_annot.3.res.oracle

tests/syntax/oracle/ghost_parameters.11.res.oracle

...syntax/oracle/inconsistent_global_ghost_spec.2.res.oracle

...syntax/oracle/inconsistent_global_ghost_spec.3.res.oracle

tests/syntax/oracle/init_bts1352.res.oracle

...syntax/oracle/invalid_implicit_cast_issue_1346.res.oracle

tests/syntax/oracle/line_number.res.oracle

tests/syntax/oracle/localisation_error.res.oracle