TypeInfo generated for undeclared types

[mcavanagh]

Steps to reproduce:

1. Create a package libfoo with one file with the following contents:

   
   struct Foo {
   x, y: int;
   }

func bar() { foo: Foo; foo_p := &foo; foo_pp := &foo_p; // This triggers the type info generation for 'libfoo_Foo' }

2. Create a second package with a `main` method and `import libfoo {...}`

Ion compilation works, but the generated C will error on compilation with `error C2065: 'libfoo_Foo': undeclared identifier`.

You'll get a line similar to:
`[190] = &(TypeInfo){TYPE_PTR, .size = sizeof(void *), .align = alignof(void *), .base = TYPEID(53, TYPE_PTR, libfoo_Foo *)},`

If the `struct Foo` isn't directly used in the `main` package, the C struct def for `Foo` will never be generated.

[pervognsen]

Thanks, I'm taking a look.

[pervognsen]

Should be fixed.