add OpenAcc clause slot

Parser/spec/OpenAcc.rats

@@ -481,6 +481,7 @@ List acc_clause_list =
 
 //// abstract AccClause ;
 public AccClause acc_clause =
+<BEGINNING>
 	acc_if_clause
 /	acc_reduction_clause
 /	acc_device_clause

Parser/spec/SlotPrinting.jadd

@@ -50,4 +50,10 @@ aspect Printing {
     s.literalAppend(getString());
     s.append("#");
   }
+
+  public void SlotAccClause.prettyPrint(PrettyPrinter s) {
+    s.append("#");
+    s.literalAppend(getSlotName());
+    s.append("#");
+  }
 }

Parser/spec/SlottableFortranParser.rats

@@ -302,6 +302,17 @@ Designator designator +=
 /   <BEGINNING> ...
 ;
 
+// == AccClause Slots ===================================================
+
+//// SlotAccClause:AccClause ::= <SlotName:String> ;
+AccClause acc_clause +=
+    <DesignatorSlot> NUMBERSIGN n:slot_name (COLON A C C UNDERSCORE C L A U S E)? NUMBERSIGN
+        {
+            yyValue = new SlotAccClause(n);
+        }
+/   <BEGINNING> ...
+;
+
 // == Name Slots ===================================================
 
 //// SlotForName:Name ;

Parser/test-data/slots/acc_clause.f

+! BlockSlot
+
+  !$acc loop #MYCLAUSE#
+  do x = 0,p
+    #test#
+  end do
+
+end