[Native][tests] Fix warnings in debugger tests

kotlin-native/backend.native/tests/debugger/src/test/kotlin/org/jetbrains/kotlin/native/test/debugger/Driver.kt

@@ -32,6 +32,7 @@ class ToolDriver(
     else
         arrayOf("-target", target())
 
+    @Suppress("UNUSED_PARAMETER")
     private fun compile(output: Path, vararg args: String, argsCalculator:() -> Array<String>) {
         check(!Files.exists(output))
         val allArgs = arrayOf(*crossPlatform(), *argsCalculator())
@@ -74,9 +75,9 @@ class ToolDriver(
         DwarfUtilParser().parse(StringReader(out)).tags.toList().processor()
     }
 
-    fun swiftc(output: Path, swiftSrc: Path, vararg args: String) {
+    fun swiftc(output: Path, swiftSrc: Path, vararg args: String): String {
         val swiftProcess = subprocess(DistProperties.swiftc, "-o", output.toString(), swiftSrc.toString(), *args)
-        val out = swiftProcess.takeIf { it.process.exitValue() == 0 }?.stdout ?: error(swiftProcess.stderr)
+        return swiftProcess.takeIf { it.process.exitValue() == 0 }?.stdout ?: error(swiftProcess.stderr)
     }
 }
 

kotlin-native/backend.native/tests/debugger/src/test/kotlin/org/jetbrains/kotlin/native/test/debugger/DwarfTests.kt

@@ -1,6 +1,6 @@
 package org.jetbrains.kotlin.native.test.debugger
 
-import junit.framework.Assert.*
+import org.junit.Assert.*
 import org.junit.Ignore
 import org.junit.Test
 

kotlin-native/backend.native/tests/debugger/src/test/kotlin/org/jetbrains/kotlin/native/test/debugger/Matchers.kt

@@ -173,7 +173,7 @@ fun dwarfDumpComplexTest(test:ToolDriverHelper.()->Unit) {
 
     with(Files.createTempDirectory("dwarfdump_test_complex")) {
         toFile().deleteOnExit()
-        val driver = ToolDriverHelper(ToolDriver(), this).test()
+        ToolDriverHelper(ToolDriver(), this).test()
     }
 }
 
@@ -186,7 +186,7 @@ fun lldbComplexTest(test:ToolDriverHelper.()->Unit) {
 
     with(Files.createTempDirectory("lldb_test_complex")) {
         toFile().deleteOnExit()
-        val driver = ToolDriverHelper(ToolDriver(), this).test()
+        ToolDriverHelper(ToolDriver(), this).test()
     }
 }