[FIR] optimize ConeTypeProjection[] RAM usage for empty arrays

On the snapshot from ^KTIJ-26260 empty ConeTypeProjection arrays take about 10mb

compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/impl/Impl.kt

@@ -14,10 +14,12 @@ import org.jetbrains.kotlin.util.WeakPair
 
 class ConeClassLikeTypeImpl(
     override val lookupTag: ConeClassLikeLookupTag,
-    override val typeArguments: Array<out ConeTypeProjection>,
+    typeArguments: Array<out ConeTypeProjection>,
     isNullable: Boolean,
     override val attributes: ConeAttributes = ConeAttributes.Empty
 ) : ConeClassLikeType() {
+    override val typeArguments = if (typeArguments.isEmpty()) EMPTY_ARRAY else typeArguments
+
     override val nullability: ConeNullability = ConeNullability.create(isNullable)
 
     // Cached expanded type and the relevant session