Initial Haiku support (#13569)

* Disable PIE on Haiku for external deps

* Networking functionality lives in libnetwork on Haiku

* Disable PIE for Haiku

* Haiku support for getting CPU_COUNT

* ERRNO fix for Haiku

* Revert "Disable PIE on Haiku for external deps"

This reverts commit a2f135e553c9c8f7cc6dfa0f6456b1025a434f10.

* Revert "Disable PIE for Haiku"

This reverts commit bbd0215fbd208b8c5af7b2a0739058d2306832fb.

* Implement PIE switch on top level

and PIE switch for external modules