Fix IsNonZeroReferenceTypes to not return true if it's zero.

This is used to generate the gcmaps, so it should fix some of the
segfault issues.

Change-Id: I1cb3beb27ae91807e36c73bb2c120a5ab4895d8c
diff --git a/src/verifier/reg_type.h b/src/verifier/reg_type.h
index 9f89d07..a2fb306 100644
--- a/src/verifier/reg_type.h
+++ b/src/verifier/reg_type.h
@@ -144,13 +144,13 @@
   }
 
   bool IsReferenceTypes() const {
-    return IsReference() || IsUnresolvedReference() ||  IsZero() ||
-        IsUninitializedReference() ||  IsUninitializedThisReference() ||
+    return IsReference() || IsUnresolvedReference() || IsZero() ||
+        IsUninitializedReference() || IsUninitializedThisReference() ||
         IsUnresolvedAndUninitializedReference() || IsUnresolvedAndUninitializedThisReference();
   }
   bool IsNonZeroReferenceTypes() const {
-    return IsReference() || IsUnresolvedReference() ||  IsZero() ||
-        IsUninitializedReference() ||  IsUninitializedThisReference() ||
+    return IsReference() || IsUnresolvedReference() ||
+        IsUninitializedReference() || IsUninitializedThisReference() ||
         IsUnresolvedAndUninitializedReference() || IsUnresolvedAndUninitializedThisReference();
   }
   bool IsCategory1Types() const {