Rename PathUtil.getJdkClassesRoots to avoid confusion

Two of these methods return roots given a path to the JRE, and the third
one returns roots given a path to the _JDK_.

plugins/kapt3/test/org/jetbrains/kotlin/kapt3/test/AbstractKotlinKapt3IntegrationTest.kt

@@ -150,7 +150,7 @@ abstract class AbstractKotlinKapt3IntegrationTest : CodegenTestCase() {
             options: Map<String, String>,
             stubsOutputDir: File,
             incrementalDataOutputDir: File
-    ) : AbstractKapt3Extension(PathUtil.getJdkClassesRoots() + PathUtil.getKotlinPathsForIdeaPlugin().stdlibPath,
+    ) : AbstractKapt3Extension(PathUtil.getJdkClassesRootsFromCurrentJre() + PathUtil.getKotlinPathsForIdeaPlugin().stdlibPath,
                                emptyList(), javaSourceRoots, outputDir, outputDir,
                                stubsOutputDir, incrementalDataOutputDir, options, emptyMap(), "", true, System.currentTimeMillis(),
                                KaptLogger(true), correctErrorTypes = true

plugins/kapt3/test/org/jetbrains/kotlin/kapt3/test/AbstractKotlinKapt3Test.kt

@@ -118,7 +118,7 @@ abstract class AbstractKotlinKaptContextTest : AbstractKotlinKapt3Test() {
         val sourceOutputDir = Files.createTempDirectory("kaptRunner").toFile()
         try {
             kaptRunner.doAnnotationProcessing(emptyList(), listOf(JavaKaptContextTest.simpleProcessor()),
-                                              compileClasspath = PathUtil.getJdkClassesRoots() + PathUtil.getKotlinPathsForIdeaPlugin().stdlibPath,
+                                              compileClasspath = PathUtil.getJdkClassesRootsFromCurrentJre() + PathUtil.getKotlinPathsForIdeaPlugin().stdlibPath,
                                               annotationProcessingClasspath = emptyList(), annotationProcessors = "",
                                               sourcesOutputDir = sourceOutputDir, classesOutputDir = sourceOutputDir,
                                               additionalSources = compilationUnits, withJdk = true)