Revert commit 64fb6b4: "require a flex run to build sscan.c ..."

Author: Markus Nullmeier

Makefile

@@ -16,7 +16,7 @@ DOCS        = README.pg_sphere COPYRIGHT.pg_sphere
 REGRESS     = init tables points euler circle line ellipse poly path box index \
               contains_ops contains_ops_compat bounding_box_gist gnomo
 
-EXTRA_CLEAN = pg_sphere--1.0.sql $(PGS_SQL) sscan.c
+EXTRA_CLEAN = pg_sphere--1.0.sql $(PGS_SQL) 
 
 CRUSH_TESTS  = init_extended circle_extended