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_codegen_gcc/src/mono_item.rs

@@ -6,7 +6,7 @@ use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_middle::bug;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use rustc_middle::mir::mono::{Linkage, Visibility};
-use rustc_middle::ty::layout::{FnAbiOf, LayoutOf};
+use rustc_middle::ty::layout::{FnAbiOf, HasTypingEnv, LayoutOf};
 use rustc_middle::ty::{self, Instance, TypeVisitableExt};
 
 use crate::context::CodegenCx;
@@ -27,11 +27,8 @@ impl<'gcc, 'tcx> PreDefineCodegenMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
         let DefKind::Static { nested, .. } = self.tcx.def_kind(def_id) else { bug!() };
         // Nested statics do not have a type, so pick a dummy type and let `codegen_static` figure out
         // the gcc type from the actual evaluated initializer.
-        let ty = if nested {
-            self.tcx.types.unit
-        } else {
-            instance.ty(self.tcx, ty::ParamEnv::reveal_all())
-        };
+        let ty =
+            if nested { self.tcx.types.unit } else { instance.ty(self.tcx, self.typing_env()) };
         let gcc_type = self.layout_of(ty).gcc_type(self);
 
         let is_tls = attrs.flags.contains(CodegenFnAttrFlags::THREAD_LOCAL);