Remove warning for running the compiler under Java 6/7

Now the compiler won't even start, so no need to check this manually.

compiler/tests/org/jetbrains/kotlin/cli/AbstractCliTest.java

@@ -74,7 +74,6 @@ public abstract class AbstractCliTest extends TestCaseWithTmpdir {
                 .replace("expected version is " + JvmMetadataVersion.INSTANCE, "expected version is $ABI_VERSION$")
                 .replace("expected version is " + JsMetadataVersion.INSTANCE, "expected version is $ABI_VERSION$")
                 .replace("\\", "/")
-                .replaceAll("^.+running the Kotlin compiler under Java 6 or 7 is unsupported and will no longer be possible in a future update\\.\n", "")
                 .replace(KotlinCompilerVersion.VERSION, "$VERSION$");
 
         return normalizedOutputWithoutExitCode + exitCode;

compiler/tests/org/jetbrains/kotlin/integration/CompilerSmokeTestBase.java

@@ -43,7 +43,6 @@ public abstract class CompilerSmokeTestBase extends KotlinIntegrationTestBase {
         javaArgs.add("org.jetbrains.kotlin.cli.jvm.K2JVMCompiler");
 
         Collections.addAll(javaArgs, arguments);
-        javaArgs.add("-Xskip-java-check");
 
         return run(logName, ArrayUtil.toStringArray(javaArgs));
     }

compiler/tests/org/jetbrains/kotlin/multiplatform/AbstractMultiPlatformIntegrationTest.kt

@@ -84,7 +84,7 @@ abstract class AbstractMultiPlatformIntegrationTest : KtUsefulTestCase() {
     private fun CLICompiler<*>.compile(sources: List<File>, vararg additionalArguments: String): String = buildString {
         val (output, exitCode) = AbstractCliTest.executeCompilerGrabOutput(
                 this@compile,
-                sources.map(File::getAbsolutePath) + listOf("-Xmulti-platform", "-Xskip-java-check") + additionalArguments
+                sources.map(File::getAbsolutePath) + listOf("-Xmulti-platform") + additionalArguments
         )
         appendln("Exit code: $exitCode")
         appendln("Output:")