Incorrect Java version check

The dotty implementation of Properties.isJavaAtLeast is broken for Java
9 (Fixed in Scalac at scala/scala#5276, but
maybe we just shouldn't have a copy of Properties.scala in Dotty). The
test is useless now anyway since we only compile with 2.12 which
requires Java 8, so this code is never going to run on an older version
of the JVM.

Author: smarter

compiler/src/dotty/tools/dotc/config/CompilerCommand.scala

@@ -118,9 +118,6 @@ object CompilerCommand extends DotClass {
     else if (settings.version.value) {
       ctx.echo(versionMsg)
       Nil
-    } else if (!Properties.isJavaAtLeast("1.8")) {
-      ctx.error("Dotty requires Java 8 to run")
-      Nil
     }
     else if (shouldStopWithInfo) {
       ctx.echo(infoMessage)