Minor, set JAVA_HOME to JDK 1.8 in LauncherScriptTest

Otherwise the test would invoke the "java" executable from PATH, which
might not be 1.8, and that would cause some tests to fail because error
messages are slightly different in newer Java versions.

compiler/tests/org/jetbrains/kotlin/cli/LauncherScriptTest.kt

@@ -34,7 +34,7 @@ class LauncherScriptTest : TestCaseWithTmpdir() {
         expectedStderr: String = "",
         expectedExitCode: Int = 0,
         workDirectory: File? = null,
-        environment: Map<String, String> = emptyMap(),
+        environment: Map<String, String> = mapOf("JAVA_HOME" to KtTestUtil.getJdk8Home().absolutePath),
     ) {
         val executableFileName = if (SystemInfo.isWindows) "$executableName.bat" else executableName
         val launcherFile = File(PathUtil.kotlinPathsForDistDirectory.homePath, "bin/$executableFileName")