Add test

tests/techmap/recursive.v

@@ -0,0 +1,8 @@
+module top;
+sub s0();
+foo f0();
+endmodule
+
+module foo;
+sub s0();
+endmodule

tests/techmap/recursive_map.v

@@ -0,0 +1,4 @@
+module sub;
+    sub _TECHMAP_REPLACE_ ();
+    bar f0();
+endmodule

tests/techmap/recursive_runtest.sh

@@ -0,0 +1,3 @@
+set -ev
+
+../../yosys -p 'hierarchy -top top; techmap -map recursive_map.v -max_iter 1; select -assert-count 2 t:sub; select -assert-count 2 t:bar' recursive.v