Translates instructions: (statements and expressions) from the ast into sil

`val instructions_trans : InferModules.CContext.t ‑> InferGenerated.Clang_ast_t.stmt ‑> InferModules.CModule_type.instr_type list ‑> InferIR.Procdesc.Node.t ‑> is_destructor_wrapper:bool ‑> InferIR.Procdesc.Node.t list`

It receives the context, a list of statements from clang ast, list of custom statments to be added before clang statements and the exit node and it returns a list of cfg nodes that represent the translation of the stmts into sil.