JVM_IR: use indy SAM conversions in jvmTarget 1.8+, fix bridges

KT-44278 KT-26060 KT-42621

compiler/testData/codegen/box/invokedynamic/sam/specializedGenerics/covariantOverride.kt

@@ -0,0 +1,13 @@
+// TARGET_BACKEND: JVM
+// JVM_TARGET: 1.8
+// SAM_CONVERSIONS: INDY
+
+fun interface IFooAny {
+    fun foo(x: Any): Any
+}
+
+fun interface IFooStr : IFooAny {
+    override fun foo(x: Any): String
+}
+
+fun box() = IFooStr { x: Any -> x.toString() }.foo("OK")