[FIR] Create fake hidden versions of List.getFirst/getLast in JDK < 21

... so that overrides are marked as deprecated regardless of the JDK.

#KT-65440 Fixed

compiler/fir/checkers/checkers.jvm/src/org/jetbrains/kotlin/fir/analysis/jvm/FirJvmOverridesBackwardCompatibilityHelper.kt

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.fir.analysis.jvm
 import org.jetbrains.kotlin.builtins.jvm.JavaToKotlinClassMap
 import org.jetbrains.kotlin.fir.analysis.FirOverridesBackwardCompatibilityHelper
 import org.jetbrains.kotlin.fir.containingClassLookupTag
+import org.jetbrains.kotlin.fir.declarations.FirDeclarationOrigin
 import org.jetbrains.kotlin.fir.declarations.isJavaOrEnhancement
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 
@@ -19,6 +20,8 @@ import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
  */
 object FirJvmOverridesBackwardCompatibilityHelper : FirOverridesBackwardCompatibilityHelper() {
     override fun additionalCheck(member: FirCallableSymbol<*>): Boolean? {
+        if (member.origin == FirDeclarationOrigin.Synthetic.FakeHiddenInPreparationForNewJdk) return true
+
         if (!member.isJavaOrEnhancement) return false
         val containingClassName = member.containingClassLookupTag()?.classId?.asSingleFqName()?.toUnsafe() ?: return false
         // If the super class is mapped to a Kotlin built-in class, then we don't require `override` keyword.