Why do this? this should compile to native machine language directly if anything. Would you transform it to C first so you could edit the C? Then what if you want to make a big update using the Closure source? it will overwrite your changes.
This approach is not practical, perhaps I am failing to understand any logic as to why you would go with this approach. Portability (between processor architectures) is all I can think of but you will never achieve competitive performance if this is the case.
Good C coders write their code differently against different processors and platforms because all machines have different capabilities and resources (strength and weaknesses). The whole point these days of writing something in C to achieve the second highest performance (only behind pure assembly language) in both processor gpu/cpu/other co-processors and at the same time using as little memory as possible (both ram and NV storage).