[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/lldb/kt61131.kt

@@ -1,5 +1,5 @@
 // KIND: STANDALONE_LLDB
-// LLDB_TRACE: kt61131.txt
+
 // FILE: kt61131-1.kt
 class FooImpl : Foo {
     override fun bar() = "zzz"