Holds temporary data until we are ready to construct the full ContainerDecl AST node.
fn parseByteAlign(p: *Parse) !?Node.Index
fn parseByteAlign(p: *Parse) !?Node.Index {
_ = p.eatToken(.keyword_align) orelse return null;
_ = try p.expectToken(.l_paren);
const expr = try p.expectExpr();
_ = try p.expectToken(.r_paren);
return expr;
}