fixup! [FIR JS] KT-57200: Allow dynamic varargs

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirFunctionParameterChecker.kt

diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirFunctionParameterChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirFunctionParameterChecker.kt
index a8f0a95..2ee1382 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirFunctionParameterChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirFunctionParameterChecker.kt
@@ -63,6 +63,10 @@
 
         for (varargParameter in varargParameters) {
             val varargParameterType = varargParameter.returnTypeRef.coneType.arrayElementType() ?: continue
+            // LUB is checked to ensure varargParameterType may
+            // never be anything except `Nothing` or `Nothing?`
+            // in case it is a complex type that quantifies
+            // over many other types.
             if (varargParameterType.leastUpperBound(context.session).isNothingOrNullableNothing ||
                 (varargParameterType.isValueClass(context.session) && !varargParameterType.isUnsignedTypeOrNullableUnsignedType)
             // Note: comparing with FE1.0, we skip checking if the type is not primitive because primitive types are not inline. That

compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeBuiltinTypeUtils.kt

diff --git a/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeBuiltinTypeUtils.kt b/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeBuiltinTypeUtils.kt
index 300f4c7..865b9c7 100644
--- a/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeBuiltinTypeUtils.kt
+++ b/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeBuiltinTypeUtils.kt
@@ -19,12 +19,12 @@
 val ConeKotlinType.isNullableAny: Boolean get() = isBuiltinType(StandardClassIds.Any, true)
 val ConeKotlinType.isNothing: Boolean get() = isBuiltinType(StandardClassIds.Nothing, false)
 val ConeKotlinType.isNullableNothing: Boolean get() = isBuiltinType(StandardClassIds.Nothing, true)
-val ConeKotlinType.isNothingOrNullableNothing: Boolean get() = isAnyOfBuiltinType(setOf(StandardClassIds.Nothing))
+val ConeKotlinType.isNothingOrNullableNothing: Boolean get() = isBuiltinType(StandardClassIds.Nothing, null)
 
 val ConeKotlinType.isUnit: Boolean get() = isBuiltinType(StandardClassIds.Unit, false)
 val ConeKotlinType.isBoolean: Boolean get() = isBuiltinType(StandardClassIds.Boolean, false)
 val ConeKotlinType.isNullableBoolean: Boolean get() = isBuiltinType(StandardClassIds.Boolean, true)
-val ConeKotlinType.isBooleanOrNullableBoolean: Boolean get() = isAnyOfBuiltinType(setOf(StandardClassIds.Boolean))
+val ConeKotlinType.isBooleanOrNullableBoolean: Boolean get() = isBuiltinType(StandardClassIds.Boolean, null)
 
 val ConeKotlinType.isChar: Boolean get() = isBuiltinType(StandardClassIds.Char, false)
 val ConeKotlinType.isString: Boolean get() = isBuiltinType(StandardClassIds.String, false)