make ap_{fixed|int}_special.h work on the mac

[jmitrevs]

Description

Currently ap_int_special.h and ap_fixed_special.h cause issues on a Mac with the default toolchain because complex is ambiguous. This fix always takes the standard complex header. We just have to make sure it doesn't break things for other setups.

Type of change

• Bug fix (non-breaking change that fixes an issue)

Tests

This should be transparent to all the pytests. It has been tested locally on a mac.

Checklist

• I have read the guidelines for contributing.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• I have installed and run pre-commit on the files I edited or added.
• I have added tests that prove my fix is effective or that my feature works.