Full changelog:
- [refactor] Move TypedConstants to taichi/ir/type (#2211) (by Ye Kuang)
- [refactor] Move ASTBuilder and FrontendContext to frontend_ir (#2210) (by bx2k)
- [ir] [transforms] Added assertion that indices won't cause overflow under debug mode (#2199) (by Jiasheng Zhang)
- [refactor] Move code away from lang_utils (#2209) (by Ye Kuang)
- [refactor] Move type related utils away from lang_util.h (#2206) (by Ye Kuang)
- [refactor] Add SNode::GradInfoProvider to isolate SNode from Expr (#2207) (by Ye Kuang)
- [refactor] Separate SNode read/write kernels into a dedicated class (#2205) (by Ye Kuang)
- [IR] Add an IR Builder with some basic functions (#2204) (by xumingkuan)
- [test] Add a basic unit test using googletest (#2201) (by Ye Kuang)
- [refactor] Make taichi/common self contained (#2200) (by Ye Kuang)
- [ir] Generate yaml documentation for statement classes (#2192) (by xumingkuan)
- [test] Add googletest as a submodule (#2197) (by Ye Kuang)
- [test] [opengl] Avoid floor division cornor cases by adjusting test data (#2191) (by bx2k)
- [Bug] [lang] Fix AST not being transformed inside ti.ndrange (#2187) (by 彭于斌)