Don't emit arg count diagnostics for method calls with unknown receiver

Fixes #7098.

1 files changed, 4 insertions, 0 deletions

diff --git a/crates/hir_ty/src/lib.rs b/crates/hir_ty/src/lib.rs
index 357bd92f9..e00c7e176 100644
--- a/crates/hir_ty/src/lib.rs
+++ b/crates/hir_ty/src/lib.rs
@@ -791,6 +791,10 @@ impl Ty {
         matches!(self, Ty::Apply(ApplicationTy { ctor: TypeCtor::Never, .. }))
     }
 
+    pub fn is_unknown(&self) -> bool {
+        matches!(self, Ty::Unknown)
+    }
+
     /// If this is a `dyn Trait` type, this returns the `Trait` part.
     pub fn dyn_trait_ref(&self) -> Option<&TraitRef> {
         match self {