fix sharing bug (broken AST) with goto which points to a labeled statement which must be instrumented

ambiguity in the segment-based shadow memory model of E-ACSL

[typing] improve typing of operators by preventing propagation of the context to the operands. This way, it prevents to introduce useless type coercions. Indeed, the typing context is only useful to limit the number of generated casts when typing the _result_ of the operation.

option