compiler: fix hardcoded zig path and restore array integration test

[Prestgg1]

Goal

Fix the compiler crate to properly resolve the Zig compiler path and restore disabled tests.

Current Issues

1. Hardcoded Zig path

compiler/src/builder.rs line 6:

/* TODO: PathBuf a gələcəkdə baxarsan */

The Zig compiler path is hardcoded as "zig" instead of using proper PathBuf resolution.

2. Disabled integration test

compiler/src/tests/compiler_test.rs: compiler_array() test function is commented out.

3. Incomplete struct/union compilation

The compiler may need fixes to support full struct and union type compilation.