Added functions to portably manipulate process context

src/x86/context.c

@@ -42,4 +42,24 @@ void destroy_context(void *ctx)
 void save_context(struct process_context_t *context)
 {
     store_active_context(context, sizeof(*context));
+}
+
+void set_context_pc(struct process_context_t *context, void *pc)
+{
+    context->eip = pc;
+}
+
+void set_context_stack(struct process_context_t *context, void *stack)
+{
+    context->esp = stack;
+}
+
+void set_context_flags(struct process_context_t *context, unsigned long flags)
+{
+    context->flags = flags;
+}
+
+void set_context_return(struct process_context_t *context, unsigned long value)
+{
+    context->eax = value;
 }