Bug: when compiling executable, emcc "forgets" provided needed library

Reproducing:

```
// src/foo.c
#include
#include

void bar();

void foo() {
printf("Foo \n");
bar();
}
```

```
// src/bar.c
#include
#include

void bar() {
printf("Bar \n");
}
```

```
// src/main.c
void foo();

int main()
{
foo();
return 0;
}
```

Compilation:
```
emcc -o src/bar.o -c -fPIC -DPIC src/bar.c
emcc -o bar.so -sSIDE_MODULE=2 -sEXPORTED_FUNCTIONS=_bar src/bar.o

emcc -o src/foo.o -fPIC -DPIC -c src/foo.c
emcc -o foo.so src/foo.o -sEXPORTED_FUNCTIONS=_foo -sSIDE_MODULE=2 bar.so

emcc -o src/main.o -c -fPIC -DPIC src/main.c
emcc -o main src/main.o -sMAIN_MODULE -sFETCH foo.so bar.so
```

This will throw the error:
```
emcc: error: foo.so: shared library dependency not found: `bar.so`
```
Expected: The file should compile without any errors. Since bar.so is
provided.