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/launcher/legacyAssertEnabled.kt

@@ -0,0 +1,44 @@
+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 main() {
+    if (!checkTrue()) error("FAIL 1")
+    if (!checkTrueWithMessage()) error("FAIL 3")
+
+    try {
+        checkFalse()
+        error("FAIL 5")
+    } catch (ignore: AssertionError) {
+    }
+
+    try {
+        checkFalseWithMessage()
+        error("FAIL 7")
+    } catch (ignore: AssertionError) {
+    }
+}