remove "unnecessary if statement" error
this "depends on compile variable" code is too hard to validate,
and has false negatives. not worth it right now.
std.str removed, instead use std.mem.
std.mem.eql and std.mem.sliceEql merged and do not require explicit
type argument.
* comptime expression is a block expression as it should be
* fix var args when number of args passed is 0
* implement const value equality for structs
* fix indent when rendering container decl AST
* IR: prevent duplicate generation of code when it is partially
compile-time evaluated
* implement compile time struct field pointer evaluation
* fix compile time evaluation of slicing
Andrew Kelley