Run classifier usage checkers after all imports are resolved

Otherwise the diagnostic was not reported on an unused import of a deprecated
class in diagnostic tests, see the test case

compiler/frontend/src/org/jetbrains/kotlin/resolve/LazyTopDownAnalyzer.kt

@@ -209,10 +209,10 @@ class LazyTopDownAnalyzer(
 
         bodyResolver.resolveBodies(c)
 
-        ClassifierUsageChecker.check(declarations, trace, classifierUsageCheckers)
-
         resolveImportsInAllFiles(c)
 
+        ClassifierUsageChecker.check(declarations, trace, classifierUsageCheckers)
+
         return c
     }