fix: large bunx changes, mostly for better windows support (#9143)

* make bun-debug properly override `bun` in path

* windows path

* fix more issues with bunx

* sync

* stuff

* stuff

* f

* stuff

* further work

* a

* [autofix.ci] apply automated fixes

* okay

* fix building on posix systems

* ok

* make it so bun create cant crash + review

* docuemnt why return false is ok

* .

* cache bust

* merge

* yeah

* yea

* Update src/install/install.zig

* review results

* this will probably fix hardlink issue on windwo

* okay

* how did that work before

---------

Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

src/string_immutable.zig

@@ -5388,7 +5388,7 @@ pub fn convertUTF8toUTF16InBuffer(
     //
     // the reason i didn't implement the fallback is purely because our
     // code in this file is too chaotic. it is left as a TODO
-    if (input.len == 0) return &[_]u16{};
+    if (input.len == 0) return buf[0..0];
     const result = bun.simdutf.convert.utf8.to.utf16.le(input, buf);
     return buf[0..result];
 }