Revert "remove redundant initializations"

This reverts commit 56c5cd10d7.

IV/wm.sql

@@ -254,6 +254,8 @@ declare
   j int4;
   multi geometry;
 begin
+  mutated = false;
+
   <<bendloop>>
   for i in 1..array_length(bends, 1) loop
     continue when abs(inflection_angle(bends[i])) <= pi;
@@ -310,6 +312,7 @@ declare
   p2 geometry;
   p3 geometry;
 begin
+  angle = 0;
   for p0 in select geom from st_dumppoints(bend) order by path[1] asc loop
     p3 = p2;
     p2 = p1;
@@ -489,6 +492,7 @@ begin
         );
       end if;
 
+
       if mutated then
         lines[i] = st_linemerge(st_union(bends));
         stagenum = stagenum + 1;