[HL API] Fix FE10 implementation of KtExpressionTypeProvider

analysis/analysis-api-fe10/src/org/jetbrains/kotlin/analysis/api/descriptors/components/KtFe10ExpressionTypeProvider.kt

@@ -72,8 +72,13 @@ class KtFe10ExpressionTypeProvider(
 
             if (typeReference != null) {
                 val bindingContext = analysisContext.analyze(typeReference, AnalysisMode.PARTIAL)
-                val kotlinType = bindingContext[BindingContext.TYPE, typeReference]
-                    ?: ErrorUtils.createErrorType(ErrorTypeKind.RETURN_TYPE, typeReference.text)
+                val kotlinType =
+                    if (declaration is KtParameter && declaration.isVarArg) {
+                        // we want full Array<out T> type for parity with FIR implementation
+                        bindingContext[BindingContext.VALUE_PARAMETER, declaration]?.returnType
+                    } else {
+                        bindingContext[BindingContext.TYPE, typeReference]
+                    } ?: ErrorUtils.createErrorType(ErrorTypeKind.RETURN_TYPE, typeReference.text)
 
                 return kotlinType.toKtType(analysisContext)
             }

analysis/analysis-api-fe10/tests-gen/org/jetbrains/kotlin/analysis/api/fe10/test/cases/generated/cases/components/expressionTypeProvider/Fe10IdeNormalAnalysisSourceModuleDeclarationReturnTypeTestGenerated.java

@@ -93,4 +93,10 @@ public class Fe10IdeNormalAnalysisSourceModuleDeclarationReturnTypeTestGenerated
     public void testTypeParameters() throws Exception {
         runTest("analysis/analysis-api/testData/components/expressionTypeProvider/declarationReturnType/typeParameters.kt");
     }
+
+    @Test
+    @TestMetadata("varargParam.kt")
+    public void testVarargParam() throws Exception {
+        runTest("analysis/analysis-api/testData/components/expressionTypeProvider/declarationReturnType/varargParam.kt");
+    }
 }