translations(rustc_session): migrate 80% of the file parse.rs

This commit migrates around 80% of the parse file to use SsessionDiagnostic
We still have to migrate struct_err and struct_warn.

compiler/rustc_session/src/lib.rs

@@ -8,8 +8,6 @@
 #![feature(map_many_mut)]
 #![recursion_limit = "256"]
 #![allow(rustc::potential_query_instability)]
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 
 #[macro_use]
 extern crate rustc_macros;