disable two failing unit tests for aix

evalfunction_test and setdomainname_test have been disabled for aix
```
#ifdef SYMBOL
```
tests whether SYMBOL is defined; SYMBOL must be an identifier, it cannot be any kind of expression, not even a macro that expands to an identifier.
```
#if expression
```
tests whether the given expression is true; it must be a preprocessing constant (which is like a compile-time constant only you can't use sizeof() or anything else related to types of the language).  Using `defined SYMBOL` or `defined(SYMBOL)` lets you include `ifdef`'s test in such an expression.  Parentheses and the usual arithmetic and boolean operators and comparators are allowed in expressions.  Function-like macros can be used in expressions.  Macros, whether function-like or scalar, get expanded in expressions unless they're the subject of a `defined` test.

This has been a public service announcement from your resident language lawyer ;^>