Fix performance issue for case when there are a lot of warnings in file

There was a problem with `reportDiagnosticOnce` method which was
 called, for example, to report diagnostics about experimentalities. It
 was crucial for code as in the issue (KT-34204).

 The whole complexity was "count of experimental diagnostics" multiply
 "count of all diagnostics" multiply very large constant. Almost on
 each `reportDiagnosticOnce` method `readonlyView()` was called which
 in turn called computation of cache. During cache computation we were
 iterating through the all diagnostics and also were using
 KotlinSuppressCache, which is not very fast.

 #KT-34204 Fixed

compiler/backend/src/org/jetbrains/kotlin/codegen/state/GenerationState.kt

@@ -336,6 +336,9 @@ private class LazyJvmDiagnostics(compute: () -> Diagnostics) : Diagnostics {
 
     override fun noSuppression() = delegate.noSuppression()
 
+    override fun hasDiagnostic(diagnostic: Diagnostic) =
+        delegate.hasDiagnostic(diagnostic)
+
     override fun iterator() = delegate.iterator()
 }