Use platform-independent line separator in jspecify tests handler

compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/classic/handlers/JspecifyDiagnosticComplianceHandler.kt

@@ -30,7 +30,7 @@ class JspecifyDiagnosticComplianceHandler(testServices: TestServices) : ClassicF
                 val jspecifyMark = diagnosticsToJspecifyMarks.getValue(jspecifyMode)[metaInfo.diagnostic.factory] ?: continue
                 val fileLines = ktFile.text.lines()
                 val fileLinePositions =
-                    fileLines.map { it.length }.runningReduce { sumLength, length -> sumLength + length + System.lineSeparator().length }
+                    fileLines.map { it.length }.runningReduce { sumLength, length -> sumLength + length + 1 }
                 val lineIndexToPasteJspecifyMark = fileLinePositions.indexOfLast { it < metaInfo.start }
                 val positionToPasteJspecifyMark = fileLinePositions[lineIndexToPasteJspecifyMark]
                 val offset = fileLines[lineIndexToPasteJspecifyMark + 1].takeWhile { it == ' ' }.length

compiler/tests-common-new/tests/org/jetbrains/kotlin/test/preprocessors/JspecifyMarksCleanupPreprocessor.kt

@@ -14,6 +14,6 @@ class JspecifyMarksCleanupPreprocessor(testServices: TestServices) : SourceFileP
 
     companion object {
         private val jspecifyMarks = diagnosticsToJspecifyMarks.values.map { it.values }.flatten().joinToString("|")
-        private val regexToCleanup = Regex("""[ ]*// ($jspecifyMarks)(, ($jspecifyMarks))*${System.lineSeparator()}""")
+        private val regexToCleanup = Regex("""[ ]*// ($jspecifyMarks)(, ($jspecifyMarks))*\n""")
     }
 }

compiler/tests-common-new/tests/org/jetbrains/kotlin/test/runners/AbstractForeignAnnotationsTest.kt

@@ -87,8 +87,8 @@ abstract class AbstractForeignAnnotationsTestBase : AbstractKotlinCompilerTest()
         }
 
         forTestsMatching("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/*") {
-//            useFrontendHandlers(::JspecifyDiagnosticComplianceHandler)
+            useFrontendHandlers(::JspecifyDiagnosticComplianceHandler)
-//            useSourcePreprocessor(::JspecifyMarksCleanupPreprocessor)
+            useSourcePreprocessor(::JspecifyMarksCleanupPreprocessor)
         }
     }
 }

compiler/tests-compiler-utils/tests/org/jetbrains/kotlin/test/MockLibraryUtil.kt

@@ -121,7 +121,7 @@ object MockLibraryUtil {
                 add("-d")
                 add(classesDir.path)
 
-                if (useJava9) {
+                if (useJava9 && extraModulepath.isNotEmpty()) {
                     add("--module-path")
                     add(extraModulepath.joinToString(File.pathSeparator))
                 }