Get rid of native_library projection queries

They don't seem particularly useful as I don't expect
native libraries to change frequently.

compiler/rustc_session/src/utils.rs

@@ -53,6 +53,17 @@ impl NativeLibKind {
             NativeLibKind::RawDylib | NativeLibKind::Unspecified | NativeLibKind::LinkArg => false,
         }
     }
+
+    pub fn is_statically_included(&self) -> bool {
+        matches!(self, NativeLibKind::Static { .. })
+    }
+
+    pub fn is_dllimport(&self) -> bool {
+        matches!(
+            self,
+            NativeLibKind::Dylib { .. } | NativeLibKind::RawDylib | NativeLibKind::Unspecified
+        )
+    }
 }
 
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Encodable, Decodable)]