Improve C litmus grammar (#887)

Signed-off-by: Hernan Ponce de Leon <[email protected]>
Co-authored-by: Hernan Ponce de Leon <[email protected]>

Author: hernanponcedeleon

dartagnan/src/main/antlr4/C11Lexer.g4

@@ -7,9 +7,9 @@ C11AtomicStore                :   'atomic_store';
 C11AtomicXchgExplicit         :   'atomic_exchange_explicit';
 C11AtomicXchg                 :   'atomic_exchange';
 C11AtomicSCASExplicit         :   'atomic_compare_exchange_strong_explicit';
-C11AtomicSCAS                 :   'atomic_compare_exchange_strong';
+C11AtomicSCAS                 :   'atomic_compare_exchange_strong' | 'SCAS';
 C11AtomicWCASExplicit         :   'atomic_compare_exchange_weak_explicit';
-C11AtomicWCAS                 :   'atomic_compare_exchange_weak';
+C11AtomicWCAS                 :   'atomic_compare_exchange_weak' | 'WCAS';
 C11AtomicFence                :   'atomic_thread_fence';
 C11AtomicAddExplicit          :   'atomic_fetch_add_explicit';
 C11AtomicAdd                  :   'atomic_fetch_add';

dartagnan/src/main/antlr4/LitmusC.g4

@@ -13,7 +13,7 @@ main
     ;
 
 variableDeclaratorList
-    :   LBrace (globalDeclarator Semi comment?)* RBrace (Semi)?
+    : LBrace (globalDeclarator Semi comment?)* (globalDeclarator comment?)? RBrace Semi?
     ;
 
 globalDeclarator
@@ -193,6 +193,7 @@ nre locals [IntBinaryOp op, String mo, String name]
     |   C11AtomicStore            LPar address = re  Comma value = re  RPar                                                                 # nreC11Store
 
     |   Ast? varName Equals re                                                                                                              # nreAssignment
+    |   re                                                                                                                                  # reAsNre
     |   typeSpecifier varName (Equals re)?                                                                                                  # nreRegDeclaration
 
     |   SpinLock LPar address = re RPar                                                                                                     # nreSpinLock
@@ -247,6 +248,8 @@ opCompare returns [IntCmpOp op]
 opArith returns [IntBinaryOp op]
     :   Plus    {$op = IntBinaryOp.ADD;}
     |   Minus   {$op = IntBinaryOp.SUB;}
+    |   Ast     {$op = IntBinaryOp.MUL;}
+    |   Slash   {$op = IntBinaryOp.DIV;}
     |   Amp     {$op = IntBinaryOp.AND;}
     |   Bar     {$op = IntBinaryOp.OR;}
     |   Circ    {$op = IntBinaryOp.XOR;}