Move legacy assert tests to launcher

since they are broken on JDK 11: they change Field.modifiers, which is prohibited
since JDK 9, because this private field is not exported.
Thus, we need to split the test into two: one with assertions enabled and the other
one with them disabled. Also, we need to run them in separate processes, for them
not to interfere each other.
 #KT-27176 Fixed

compiler/testData/codegen/box/assert/legacy.kt

@@ -1,76 +0,0 @@
-// TARGET_BACKEND: JVM
-// KOTLIN_CONFIGURATION_FLAGS: ASSERTIONS_MODE=legacy
-// WITH_RUNTIME
-// FULL_JDK
-
-import java.lang.reflect.Field
-import java.lang.reflect.Modifier
-
-fun setDesiredAssertionStatus(v: Boolean) {
-    @Suppress("INVISIBLE_REFERENCE")
-    val field = kotlin._Assertions.javaClass.getField("ENABLED")
-    val modifiers = Field::class.java.getDeclaredField("modifiers");
-    modifiers.isAccessible = true
-    modifiers.setInt(field, field.modifiers and Modifier.FINAL.inv())
-    field.set(null, v)
-}
-
-fun checkTrue(): Boolean {
-    var hit = false
-    val l = { hit = true; true }
-    assert(l())
-    return hit
-}
-
-fun checkTrueWithMessage(): Boolean {
-    var hit = false
-    val l = { hit = true; true }
-    assert(l()) { "BOOYA!" }
-    return hit
-}
-
-fun checkFalse(): Boolean {
-    var hit = false
-    val l = { hit = true; false }
-    assert(l())
-    return hit
-}
-
-fun checkFalseWithMessage(): Boolean {
-    var hit = false
-    val l = { hit = true; false }
-    assert(l()) { "BOOYA!" }
-    return hit
-}
-
-fun box(): String {
-    setDesiredAssertionStatus(false)
-    if (!checkTrue()) return "FAIL 0"
-    setDesiredAssertionStatus(true)
-    if (!checkTrue()) return "FAIL 1"
-
-    setDesiredAssertionStatus(false)
-    if (!checkTrueWithMessage()) return "FAIL 2"
-    setDesiredAssertionStatus(true)
-    if (!checkTrueWithMessage()) return "FAIL 3"
-
-    setDesiredAssertionStatus(false)
-    if (!checkFalse()) return "FAIL 4"
-    setDesiredAssertionStatus(true)
-    try {
-        checkFalse()
-        return "FAIL 5"
-    } catch (ignore: AssertionError) {
-    }
-
-    setDesiredAssertionStatus(false)
-    if (!checkFalseWithMessage()) return "FAIL 6"
-    setDesiredAssertionStatus(true)
-    try {
-        checkFalseWithMessage()
-        return "FAIL 7"
-    } catch (ignore: AssertionError) {
-    }
-
-    return "OK"
-}