Kotlin: Exclude .kt files from dead code queries

Author: tamasvajk

java/ql/test/kotlin/query-tests/DeadCode/DeadClass.expected

@@ -1,4 +0,0 @@
-| Test.kt:0:0:0:0 | TestKt | The class TestKt is entirely unused. | Test.kt:0:0:0:0 | TestKt | TestKt |
-| Test.kt:1:1:1:26 | DbAddexpr | The class DbAddexpr is entirely unused. | Test.kt:1:1:1:26 | DbAddexpr | DbAddexpr |
-| Test.kt:3:1:4:1 | Label | The class Label is only used from dead code originating at $@. | Test.kt:15:1:17:1 | main1 | main1 |
-| Test.kt:19:1:27:1 | Foo | The class Foo is only used from dead code originating at $@. | Test.kt:29:1:31:1 | main2 | main2 |

java/ql/test/kotlin/query-tests/DeadCode/DeadMethod.expected

@@ -1,8 +0,0 @@
-| Test.kt:0:0:0:0 | component1 | The method component1 is entirely unused. | Test.kt:0:0:0:0 | component1 | component1 |
-| Test.kt:0:0:0:0 | component2 | The method component2 is entirely unused. | Test.kt:0:0:0:0 | component2 | component2 |
-| Test.kt:0:0:0:0 | copy | The method copy is only used from dead code originating at $@. | Test.kt:0:0:0:0 | copy$default | copy$default |
-| Test.kt:0:0:0:0 | copy$default | The method copy$default is entirely unused. | Test.kt:0:0:0:0 | copy$default | copy$default |
-| Test.kt:20:10:20:41 | DC | The method DC is only used from dead code originating at $@. | Test.kt:0:0:0:0 | copy$default | copy$default |
-| Test.kt:20:10:20:41 | DC | The method DC is only used from dead code originating at $@. | Test.kt:29:1:31:1 | main2 | main2 |
-| Test.kt:20:19:20:28 | getX | The method getX is only used from dead code originating at $@. | Test.kt:29:1:31:1 | main2 | main2 |
-| Test.kt:20:31:20:40 | getY | The method getY is only used from dead code originating at $@. | Test.kt:29:1:31:1 | main2 | main2 |