MemberAttributeMacro do not visit members that are guarded with IfConfigDecl

[jaredgrubb]

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.