condition deciding whether decl or elsedecl applies
array of Dsymbol's for else block
Dsymbol's affected by this AttribDeclaration
Create a new scope if one or more given attributes are different from the sc's. If the returned scope != sc, the caller should pop the scope after it used.
A hook point to supply scope for members. addMember, setScope, importAll, semantic, semantic2 and semantic3 will use this.
A conditional compilation declaration, used for version / debug and specialized for static if.
<condition> { <decl...> } else { <elsedecl> }