Tweak CheckStyle rule so it only considers argument variables

Author: eregon

src/main/.checkstyle_checks.xml

@@ -208,7 +208,7 @@
       <property name="message" value="Don't use transferToInterpreterOnException"/>
     </module>
     <module name="RegexpSinglelineJava">
-      <property name="format" value='"isRuby(?!Value|DynamicObject|SymbolOrString|Rational|Range|[^"]+\|\|)'/> <!-- Rational is not a builtin type -->
+      <property name="format" value='"isRuby(?!Value|DynamicObject|SymbolOrString|Rational|Range|[^"]+\|\|)\w+\(\w+\)'/> <!-- Rational is not a builtin type -->
       <property name="message" value="Type the argument instead of using a positive isRuby* guard."/>
     </module>
     <module name="RegexpSinglelineJava">

src/main/java/org/truffleruby/core/module/ModuleNodes.java

@@ -1235,9 +1235,7 @@ private void warnAlreadyInitializedConstant(RubyModule module, String name,
     @ImportStatic(RubyArguments.class)
     public abstract static class DefineMethodNode extends AlwaysInlinedMethodNode {
 
-        //Checkstyle: stop
         @Specialization(guards = { "isMethodParameterProvided(rubyArgs)", "isRubyMethod(getArgument(rubyArgs, 1))" })
-        //Checkstyle: resume
         protected RubySymbol defineMethodWithMethod(
                 Frame callerFrame, RubyModule module, Object[] rubyArgs, RootCallTarget target,
                 @Cached NameToJavaStringNode nameToJavaStringNode) {
@@ -1247,9 +1245,7 @@ protected RubySymbol defineMethodWithMethod(
             return addMethod(module, name, (RubyMethod) method);
         }
 
-        //Checkstyle: stop
         @Specialization(guards = { "isMethodParameterProvided(rubyArgs)", "isRubyProc(getArgument(rubyArgs, 1))" })
-        //Checkstyle: resume
         protected RubySymbol defineMethodWithProc(
                 Frame callerFrame, RubyModule module, Object[] rubyArgs, RootCallTarget target,
                 @Cached NameToJavaStringNode nameToJavaStringNode) {
@@ -1260,10 +1256,8 @@ protected RubySymbol defineMethodWithProc(
             return addProc(module, name, (RubyProc) method, callerFrame.materialize());
         }
 
-        //Checkstyle: stop
         @Specialization(
                 guards = { "isMethodParameterProvided(rubyArgs)", "isRubyUnboundMethod(getArgument(rubyArgs, 1))" })
-        //Checkstyle: resume
         protected RubySymbol defineMethodWithUnboundMethod(
                 Frame callerFrame, RubyModule module, Object[] rubyArgs, RootCallTarget target,
                 @Cached NameToJavaStringNode nameToJavaStringNode) {