Set the ruby home with javaProperties for TRUFFLERUBY-TEST and TRUFFLERUBY-TCK

* It also seems to work to set javaProperties on the TRUFFLERUBY distribution
  but that is some kind of cyclic dependency that is probably best to avoid.

Author: eregon

mx.truffleruby/suite.py

@@ -513,14 +513,21 @@
             "distDependencies": [
                 "TRUFFLERUBY",
                 "TRUFFLERUBY-SERVICES",
+                "TRUFFLERUBY_GRAALVM_SUPPORT",
             ],
+            "javaProperties": {
+                "org.graalvm.language.ruby.home": "<path:TRUFFLERUBY_GRAALVM_SUPPORT>"
+            },
             "license": ["EPL-2.0"],
         },
 
         "TRUFFLERUBY-TCK": {
             "testDistribution": True,
             "dependencies": ["org.truffleruby.tck"],
             "distDependencies": ["truffle:TRUFFLE_TCK"],
+            "javaProperties": {
+                "org.graalvm.language.ruby.home": "<path:TRUFFLERUBY_GRAALVM_SUPPORT>"
+            },
             "license": ["EPL-2.0"],
         },
     },

tool/jt.rb

@@ -1024,9 +1024,6 @@ def test(*args)
       unittest_options, tests = unittest_args.partition { |arg| arg.start_with?('-') }
       tests = tests.empty? ? ['org.truffleruby'] : tests
       # TODO (eregon, 4 Feb 2019): This should run on GraalVM, not development jars
-      # The home needs to be set, otherwise TruffleFile does not allow access to files in the TruffleRuby home,
-      # because it cannot find the correct home.
-      unittest_options << "-Dorg.graalvm.language.ruby.home=#{ruby_home}"
       mx(*mx_options, 'unittest', *unittest_options, *tests)
     when 'tck' then mx 'tck', *rest
     else