feat: add more module tests (#492)

* Update rom example

The rom/romlex example now compiles.  However, we still need some test
traces.

* Add mod / mul examples.

* Add tests for mod/mul/gas/mmu/exp/rom

This adds tests for these modules, along with suitable test traces.
However, exp and mmu currently require perspectives, so these tests are
not enabled.

pkg/test/valid_corset_test.go

@@ -825,6 +825,32 @@ func TestSlow_Mmio(t *testing.T) {
 	Check(t, true, "mmio")
 }
 
+func TestSlow_Rom(t *testing.T) {
+	Check(t, true, "rom")
+}
+
+/*
+func TestSlow_Mmu(t *testing.T) {
+	Check(t, true, "mmu")
+} */
+
+func TestSlow_Gas(t *testing.T) {
+	Check(t, true, "gas")
+}
+
+/* #396
+   func TestSlow_Exp(t *testing.T) {
+	Check(t, true, "exp")
+} */
+
+func TestSlow_Mul(t *testing.T) {
+	Check(t, true, "mul")
+}
+
+func TestSlow_Mod(t *testing.T) {
+	Check(t, true, "mod")
+}
+
 // ===================================================================
 // Test Helpers
 // ===================================================================