Thread safety for status updates, periodically minify

vm/program.go

@@ -6,3 +6,17 @@ type Program struct {
 	InstructionLimit   uint64
 	Functions          []*Function
 }
+
+func (prog *Program) Copy() *Program {
+	ret := &Program{
+		GlobalMemorySize:   prog.GlobalMemorySize,
+		FunctionMemorySize: prog.FunctionMemorySize,
+		InstructionLimit:   prog.InstructionLimit,
+	}
+
+	for _, fnc := range prog.Functions {
+		ret.Functions = append(ret.Functions, fnc.Copy())
+	}
+
+	return ret
+}