[Analysis API FIR] add check for public api

analysis/analysis-api/src/org/jetbrains/kotlin/analysis/api/components/KtVisibilityCheckerMixIn.kt

@@ -18,6 +18,8 @@ public abstract class KtVisibilityChecker : KtAnalysisSessionComponent() {
         position: PsiElement,
         receiverExpression: KtExpression?
     ): Boolean
+
+    public abstract fun isPublicApi(symbol: KtSymbolWithVisibility): Boolean
 }
 
 public interface KtVisibilityCheckerMixIn : KtAnalysisSessionMixIn {
@@ -29,4 +31,13 @@ public interface KtVisibilityCheckerMixIn : KtAnalysisSessionMixIn {
     ): Boolean = withValidityAssertion {
         analysisSession.visibilityChecker.isVisible(candidateSymbol, useSiteFile, position, receiverExpression)
     }
+
+    /**
+     * Returns true for effectively public symbols, including internal declarations with @PublishedApi annotation.
+     * In 'Explicit API' mode explicit visibility modifier and explicit return types are required for such symbols.
+     * See FirExplicitApiDeclarationChecker.kt
+     */
+    public fun isPublicApi(symbol: KtSymbolWithVisibility): Boolean = withValidityAssertion {
+        analysisSession.visibilityChecker.isPublicApi(symbol)
+    }
 }