compiler: move ReplacePanicsWithTrap pass to transforms

This moves the transformation pass to the right location, and adds tests
to see that it actually works correctly.

transform/panic_test.go

@@ -0,0 +1,10 @@
+package transform
+
+import (
+	"testing"
+)
+
+func TestReplacePanicsWithTrap(t *testing.T) {
+	t.Parallel()
+	testTransform(t, "testdata/panic", ReplacePanicsWithTrap)
+}