MemberAttributeMacro do not visit members that are guarded with IfConfigDecl

### Description

The `MemberAttributeMacro` does not get invoked for members that are inside `#if` guards.

### Steps to Reproduce

Looking at the unit tests, I can add a new one to the MemberAttributeMacroTests:
```
func testAttributeWithIfConfigDecl() {
assertMacroExpansion(
"""
@wrapAllProperties struct S {
#if true
var value = 1
#endif
}
""",
expandedSource: """
struct S {
#if true
@Wrapper
var value = 1
#endif
}
""",
macros: ["wrapAllProperties": WrapAllProperties.self],
indentationWidth: indentationWidth
)
}
```

Actual results is the macro never gets visited for `value` at all.