Transpiling two and more C code

[Konstantin8105]

Example:
File one.c:

#include "head.h"
int main(){
        say();
        return 0;
}

File head.h:

void say();

File two.c:

include<stdio.h>
void say(){
        printf("42");
}

Command line for checking in gcc - gcc -c one.c; gcc -c two.c ; gcc -o pr one.o two.o; ./pr
Result: 42

Command line for checking clang - clang -E two.c one.c. Result is like usually.
So, with little modifications of project - we can support a multiply C code transpilation, but now we will have one big single result Go code.

Reason:
It is need for transpilation of project https://www.cs.cmu.edu/~quake/triangle.html.

[elliotchance]

This is a duplicate of #63