Migrate compiler, idea and others to new case conversion api

plugins/kapt3/kapt3-base/test/JavaKaptContextTest.kt

@@ -36,7 +36,8 @@ class JavaKaptContextTest : TestCase() {
                         val annotatedElements = roundEnv.getElementsAnnotatedWith(annotation)
 
                         for (annotatedElement in annotatedElements) {
-                            val generatedClassName = annotatedElement.simpleName.toString().capitalize() + annotationName.capitalize()
+                            val generatedClassName = annotatedElement.simpleName.toString().replaceFirstChar(Char::uppercaseChar) +
+                                    annotationName.replaceFirstChar(Char::uppercaseChar)
                             val file = processingEnv.filer.createSourceFile("generated." + generatedClassName)
                             file.openWriter().use {
                                 it.write(

plugins/kapt3/kapt3-base/test/KaptPathsTest.kt

@@ -15,7 +15,7 @@ import java.nio.file.Files
 class KaptPathsTest : TestCase() {
     @Test
     fun testSymbolicLinks() {
-        if (System.getProperty("os.name").toLowerCase().contains("win")) return
+        if (System.getProperty("os.name").lowercase().contains("win")) return
         val tempDir = Files.createTempDirectory("kapt-test").toFile()
         try {
             fun File.writeJavaClass() = apply {