K2 LL API: implement automatic diagnostic suppression

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/collectors/components/AbstractDiagnosticCollectorComponent.kt

@@ -10,7 +10,6 @@ import org.jetbrains.kotlin.fir.FirElement
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
 import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
-import org.jetbrains.kotlin.diagnostics.impl.PendingDiagnosticsCollectorWithSuppress
 import org.jetbrains.kotlin.fir.declarations.FirFile
 import org.jetbrains.kotlin.fir.visitors.FirVisitor
 
@@ -21,10 +20,8 @@ abstract class AbstractDiagnosticCollectorComponent(
     override fun visitElement(element: FirElement, data: CheckerContext) {}
 
     protected fun checkAndCommitReportsOn(element: FirElement, context: DiagnosticContext?) {
-        if (reporter is PendingDiagnosticsCollectorWithSuppress) {
-            val source = element.source ?: return
-            reporter.checkAndCommitReportsOn(source, context, context == null)
-        }
+        val source = element.source ?: return
+        reporter.checkAndCommitReportsOn(source, context)
     }
 
     open fun endOfFile(file: FirFile) {}

compiler/frontend.common/src/org/jetbrains/kotlin/diagnostics/DiagnosticReporter.kt

@@ -27,6 +27,9 @@ abstract class MutableDiagnosticContext : DiagnosticContext {
 
 abstract class DiagnosticReporter {
     abstract fun report(diagnostic: KtDiagnostic?, context: DiagnosticContext)
+
+    open fun checkAndCommitReportsOn(element: AbstractKtSourceElement, context: DiagnosticContext?) {
+    }
 }
 
 open class KtDiagnosticReporterWithContext(

compiler/frontend.common/src/org/jetbrains/kotlin/diagnostics/impl/PendingDiagnosticsCollectorWithSuppress.kt

@@ -29,11 +29,11 @@ class PendingDiagnosticsCollectorWithSuppress : BaseDiagnosticsCollector() {
         }
     }
 
-    fun checkAndCommitReportsOn(
+    override fun checkAndCommitReportsOn(
         element: AbstractKtSourceElement,
-        context: DiagnosticContext?,
-        commitEverything: Boolean
+        context: DiagnosticContext?
     ) {
+        val commitEverything = context == null
         for ((path, pendingList) in pendingDiagnosticsByFilePath) {
             val committedList = _diagnosticsByFilePath.getOrPut(path) { mutableListOf() }
             val iterator = pendingList.iterator()