Add compound segment experiment flag

Change-Id: Id80f76ea2598daa93e693c5efe29b782abe33957
diff --git a/av1/encoder/rdopt.c b/av1/encoder/rdopt.c
index a701e80..70b93b9 100644
--- a/av1/encoder/rdopt.c
+++ b/av1/encoder/rdopt.c
@@ -4382,6 +4382,11 @@
   switch (comp_type) {
     case COMPOUND_AVERAGE: return 0;
     case COMPOUND_WEDGE: return get_interinter_wedge_bits(bsize);
+#if CONFIG_COMPOUND_SEGMENT
+    // TODO(sarahparker) this 0 is just a placeholder, it is possible this will
+    // need to change once this mode is fully implemented
+    case COMPOUND_SEG: return 0;
+#endif  // CONFIG_COMPOUND_SEGMENT
     default: assert(0); return 0;
   }
 }
@@ -7605,6 +7610,9 @@
             }
           }
           break;
+#if CONFIG_COMPOUND_SEGMENT
+        case COMPOUND_SEG: break;
+#endif  // CONFIG_COMPOUND_SEGMENT
         default: assert(0); return 0;
       }
     }