[Native] Drop LLDB_TRACE test directive

This directive doesn't have a lot of meaning. It is always set this
way that we are getting text file with the same name as test file.

native/native.tests/testData/samples/standalone_lldb_stepping.kt

@@ -1,5 +1,5 @@
 // KIND: STANDALONE_LLDB
-// LLDB_TRACE: standalone_lldb_stepping.txt
+
 import kotlin.test.*
 
 fun main(args: Array<String>) {