Remove unreachable instructions

src/cpp/parse.cpp

@@ -2386,8 +2386,6 @@ bool Parser::optAttribute(typet &t)
       return false;
     }
   }
-
-  return true;
 }
 
 /*

src/goto-cc/as_mode.cpp

@@ -366,7 +366,7 @@ int as_modet::as_hybrid_binary()
 
   #else
   error() << "binary merging not implemented for this platform" << eom;
-  return 1;
+  result = 1;
   #endif
 
   return result;

src/pointer-analysis/goto_program_dereference.cpp

@@ -54,14 +54,11 @@ bool goto_program_dereferencet::is_valid_object(
     return true; // global/static
 
   #if 0
-  if(valid_local_variables->find(symbol.name)!=
-     valid_local_variables->end())
-    return true; // valid local
+  return valid_local_variables->find(symbol.name)!=
+     valid_local_variables->end(); // valid local
   #else
   return true;
   #endif
-
-  return false;
 }
 
 void goto_program_dereferencet::dereference_failure(

src/util/simplify_expr_int.cpp

@@ -1483,9 +1483,6 @@ bool simplify_exprt::simplify_inequality(exprt &expr)
     // both are not constant
     return simplify_inequality_not_constant(expr);
   }
-
-  UNREACHABLE;
-  return false;
 }
 
 bool simplify_exprt::eliminate_common_addends(

src/util/simplify_expr_pointer.cpp

@@ -403,8 +403,6 @@ bool simplify_exprt::simplify_pointer_offset(exprt &expr)
 
       return false;
     }
-
-    return true;
   }
 
   return true;