Check TrufflePrimitive is called syntactically

Author: pitr-ch

spec/truffle/graal/assert_constant_spec.rb

@@ -11,7 +11,7 @@
 describe "TrufflePrimitive.assert_compilation_constant" do
 
   it "raises a RuntimeError when called dynamically" do
-    -> { Truffle::Graal.send(:assert_constant, 14 + 2) }.should raise_error(RuntimeError)
+    -> { tp = TrufflePrimitive; tp.assert_constant(14 + 2) }.should raise_error(RuntimeError)
   end
 
   guard -> { !TruffleRuby.jit? } do

spec/truffle/graal/assert_not_compiled_spec.rb

@@ -11,7 +11,7 @@
 describe "TrufflePrimitive.assert_not_compiled" do
 
   it "raises a RuntimeError when called dynamically" do
-    -> { Truffle::Graal.send(:assert_not_compiled) }.should raise_error(RuntimeError)
+    -> { tp = TrufflePrimitive; tp.assert_not_compiled }.should raise_error(RuntimeError)
   end
 
   guard -> { !TruffleRuby.jit? } do

src/main/java/org/truffleruby/core/CoreLibrary.java

@@ -1520,6 +1520,7 @@ public DynamicObject getStructClass() {
             "/core/truffle/string_operations.rb",
             "/core/truffle/backward.rb",
             "/core/truffle/truffleruby.rb",
+            "/core/truffle/truffle_primitive.rb",
             "/core/splitter.rb",
             "/core/stat.rb",
             "/core/io.rb",

src/main/ruby/truffleruby/core/truffle/truffle_primitive.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+# Copyright (c) 2019 Oracle and/or its affiliates. All rights reserved. This
+# code is released under a tri EPL/GPL/LGPL license. You can use it,
+# redistribute it and/or modify it under the terms of the:
+#
+# Eclipse Public License version 2.0, or
+# GNU General Public License version 2, or
+# GNU Lesser General Public License version 2.1.
+
+module TrufflePrimitive
+
+  def self.method_missing(name, *args, &block)
+    raise "TrufflePrimitive.#{name} has to be called syntactically."
+  end
+
+end