use TypingEnv when no infcx is available

the behavior of the type system not only depends on the current
assumptions, but also the currentnphase of the compiler. This is
mostly necessary as we need to decide whether and how to reveal
opaque types. We track this via the `TypingMode`.

compiler/rustc_metadata/src/native_libs.rs

@@ -6,7 +6,7 @@ use rustc_ast::CRATE_NODE_ID;
 use rustc_attr as attr;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_middle::query::LocalCrate;
-use rustc_middle::ty::{List, ParamEnv, ParamEnvAnd, Ty, TyCtxt};
+use rustc_middle::ty::{self, List, Ty, TyCtxt};
 use rustc_session::Session;
 use rustc_session::config::CrateType;
 use rustc_session::cstore::{
@@ -613,7 +613,7 @@ impl<'tcx> Collector<'tcx> {
             .map(|ty| {
                 let layout = self
                     .tcx
-                    .layout_of(ParamEnvAnd { param_env: ParamEnv::empty(), value: ty })
+                    .layout_of(ty::TypingEnv::fully_monomorphized().as_query_input(ty))
                     .expect("layout")
                     .layout;
                 // In both stdcall and fastcall, we always round up the argument size to the