Add optional SEED=n command line option to Makefile, and -S n command line option to test scripts, for deterministic regression tests.

tests/realmath/run-test.sh

@@ -1,14 +1,26 @@
 #!/bin/bash
 set -e
 
+OPTIND=1
+count=100
+seed=""    # default to no seed specified
+while getopts "c:S:" opt
+do
+    case "$opt" in
+	c) count="$OPTARG" ;;
+	S) seed="-S $OPTARG" ;;
+    esac
+done
+shift "$((OPTIND-1))"
+
 rm -rf temp
 mkdir -p temp
 echo "generating tests.."
-python3 generate.py
+python3 generate.py -c $count $seed
 
 cd temp
 echo "running tests.."
-for ((i = 0; i < 100; i++)); do
+for ((i = 0; i < $count; i++)); do
 	echo -n "[$i]"
 	idx=$( printf "%05d" $i )
 	../../../yosys -qq uut_${idx}.ys