Fix warnings in stdlib/compiler/plugins/test code

compiler/tests-spec/tests/org/jetbrains/kotlin/spec/consistency/SpecTestsConsistencyTest.kt

@@ -31,7 +31,7 @@ class SpecTestsConsistencyTest : TestCase() {
 
         @com.intellij.testFramework.Parameterized.Parameters(name = "{0}")
         @JvmStatic
-        fun getTestFiles(klass: Class<*>): List<Array<String>> {
+        fun getTestFiles(@Suppress("UNUSED_PARAMETER") klass: Class<*>): List<Array<String>> {
             val testFiles = mutableListOf<Array<String>>()
 
             TestArea.values().forEach { testArea ->

compiler/tests-spec/tests/org/jetbrains/kotlin/spec/utils/tasks/PrintSpecTestsStatistic.kt

@@ -58,10 +58,10 @@ fun notLinkedSpecTestsPrint() {
     }
 }
 
-fun main(args: Array<String>) {
+fun main() {
     println("==================================================")
     linkedSpecTestsPrint()
     println("==================================================")
     notLinkedSpecTestsPrint()
     println("==================================================")
-}
+}

compiler/tests-spec/tests/org/jetbrains/kotlin/spec/utils/validators/DiagnosticTestTypeValidator.kt

@@ -52,7 +52,7 @@ class DiagnosticTestTypeValidator(
     private fun collectDiagnostics(files: List<BaseDiagnosticsTest.TestFile>) {
         files.forEach { file ->
             file.actualDiagnostics.forEach {
-                val diagnosticName = it.diagnostic.factory.name!!
+                val diagnosticName = it.diagnostic.factory.name
                 diagnosticStats.run { put(diagnosticName, getOrDefault(diagnosticName, 0) + 1) }
                 diagnostics.add(it.diagnostic)
             }
@@ -68,4 +68,4 @@ class DiagnosticTestTypeValidator(
         val diagnostics = if (diagnosticStats.isNotEmpty()) "$diagnosticSeverityStats | $diagnosticStats" else "does not contain"
         println("DIAGNOSTICS: $diagnostics")
     }
-}
+}