KT-43286 use JVM 1.8 intrinsics for coercible unsigned values only

compiler/testData/codegen/box/unsignedTypes/kt43286.kt

@@ -0,0 +1,26 @@
+// JVM_TARGET: 1.8
+// WITH_RUNTIME
+// KJS_WITH_FULL_RUNTIME
+
+class D(val x: UInt?)
+
+class E(val x: Any)
+
+fun f(d: D): String {
+    return d.x?.let { d.x.toString() } ?: ""
+}
+
+fun g(e: E): String {
+    if (e.x is UInt) return e.x.toString()
+    return ""
+}
+
+fun box(): String {
+    val test1 = f(D(42u))
+    if (test1 != "42") throw Exception(test1)
+
+    val test2 = g(E(42u))
+    if (test2 != "42") throw Exception(test2)
+
+    return "OK"
+}

compiler/testData/codegen/box/unsignedTypes/kt43286a.kt

@@ -0,0 +1,8 @@
+// JVM_TARGET: 1.8
+// WITH_RUNTIME
+// KJS_WITH_FULL_RUNTIME
+
+fun box(): String {
+    val x = 3UL % 2U
+    return if (x == 1UL) "OK" else "Fail: $x"
+}