FIR TEST: perform more accurate check on file identity

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

@@ -31,8 +31,12 @@ class FirTestDataConsistencyHandler(testServices: TestServices) : AfterAnalysisC
             runFirTestAndGeneratedTestData(testData, firTestData)
             return
         }
-        val originalFileContent = clearTextFromDiagnosticMarkup(testData.readText())
-        val firFileContent = clearTextFromDiagnosticMarkup(firTestData.readText())
+        var originalFileContent = clearTextFromDiagnosticMarkup(testData.readText()).trim()
+        var firFileContent = clearTextFromDiagnosticMarkup(firTestData.readText()).trim()
+        if (System.lineSeparator() != "\n") {
+            originalFileContent = originalFileContent.replace("\r\n", "\n")
+            firFileContent = firFileContent.replace("\r\n", "\n")
+        }
         testServices.assertions.assertEquals(originalFileContent, firFileContent) {
             "Original and fir test data aren't identical. " +
                     "Please, add changes from ${testData.name} to ${firTestData.name}"

compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/fir/handlers/FirIdenticalChecker.kt

@@ -31,7 +31,7 @@ class FirIdenticalChecker(testServices: TestServices) : AfterAnalysisChecker(tes
         if (testDataFile.isFirTestData) {
             val firFile = helper.getFirFileToCompare(testDataFile)
             val classicFile = helper.getClassicFileToCompare(testDataFile)
-            if (helper.contentsAreEquals(classicFile, firFile)) {
+            if (helper.contentsAreEquals(classicFile, firFile, trimLines = true)) {
                 helper.deleteFirFile(testDataFile)
                 helper.addDirectiveToClassicFileAndAssert(classicFile)
             }

compiler/tests-common-new/tests/org/jetbrains/kotlin/test/utils/FirIdenticalCheckerHelper.kt

@@ -28,7 +28,7 @@ abstract class FirIdenticalCheckerHelper(private val testServices: TestServices)
 
     private fun File.readContent(trimLines: Boolean): String {
         return if (trimLines) {
-            this.readLines().map { it.trimEnd() }.joinToString("\n").trimEnd()
+            this.readLines().joinToString("\n") { it.trimEnd() }.trimEnd()
         } else {
             this.readText()
         }