Add parse location fields to NullTest and BooleanTest structs.

We did not need a location tag on NullTest or BooleanTest before, because
no error messages referred directly to their locations.  That's planned
to change though, so add these fields in a separate housekeeping commit.

Catversion bump because stored rules may change.

src/backend/nodes/readfuncs.c

@@ -1044,6 +1044,7 @@ _readNullTest(void)
 	READ_NODE_FIELD(arg);
 	READ_ENUM_FIELD(nulltesttype, NullTestType);
 	READ_BOOL_FIELD(argisrow);
+	READ_LOCATION_FIELD(location);
 
 	READ_DONE();
 }
@@ -1058,6 +1059,7 @@ _readBooleanTest(void)
 
 	READ_NODE_FIELD(arg);
 	READ_ENUM_FIELD(booltesttype, BoolTestType);
+	READ_LOCATION_FIELD(location);
 
 	READ_DONE();
 }