Kotlin: Add test cases for java/unreachable-catch-clause

Author: tamasvajk

java/ql/test/kotlin/query-tests/PartiallyMaskedCatch/PartiallyMaskedCatch.expected

@@ -0,0 +1,2 @@
+| PartiallyMaskedCatchTest.kt:18:7:20:5 | catch (...) | This catch-clause is unreachable; it is masked $@. | PartiallyMaskedCatchTest.kt:16:7:18:5 | catch (...) | by a previous catch-clause for exceptions of type 'FileNotFoundException' |
+| PartiallyMaskedCatchTest.kt:28:7:30:5 | catch (...) | This catch-clause is unreachable; it is masked $@. | PartiallyMaskedCatchTest.kt:26:7:28:5 | catch (...) | by a previous catch-clause for exceptions of type 'FileNotFoundException' |

java/ql/test/kotlin/query-tests/PartiallyMaskedCatch/PartiallyMaskedCatch.qlref

@@ -0,0 +1 @@
+Likely Bugs/Statements/PartiallyMaskedCatch.ql

java/ql/test/kotlin/query-tests/PartiallyMaskedCatch/PartiallyMaskedCatchTest.kt

@@ -0,0 +1,31 @@
+fun fn0() { throw java.io.IOException() }
+
+fun fn1() {
+    try {
+        throw java.io.IOException()
+    } catch (e: java.io.FileNotFoundException) {
+        println(e)
+    } catch (e: java.io.IOException) {
+        println(e)
+    }
+}
+
+fun fn2() {
+    try {
+        fn0()
+    } catch (e: java.io.FileNotFoundException) {
+        println(e)
+    } catch (e: java.io.IOException) {	// False positive
+        println(e)
+    }
+}
+
+fun fn3() {
+    try {
+        throw java.io.FileNotFoundException()
+    } catch (e: java.io.FileNotFoundException) {
+        println(e)
+    } catch (e: java.io.IOException) {	// True positive
+        println(e)
+    }
+}