[all-commits] [llvm/llvm-project] 892df3: Fix interaction of `constinit` and `weak`.

[Richard Smith via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 892df30a7f344b6cb9995710efbc94bb25cfb95b
      https://github.com/llvm/llvm-project/commit/892df30a7f344b6cb9995710efbc94bb25cfb95b
  Author: Richard Smith <richard at metafoo.co.uk>
  Date:   2020-09-30 (Wed, 30 Sep 2020)

  Changed paths:
    M clang/lib/AST/Decl.cpp
    M clang/lib/AST/ExprConstant.cpp
    M clang/lib/Sema/SemaDeclCXX.cpp
    A clang/test/SemaCXX/cxx20-constinit.cpp

  Log Message:
  -----------
  Fix interaction of `constinit` and `weak`.

We previously took a shortcut and said that weak variables never have
constant initializers (because those initializers are never correct to
use outside the variable). We now say that weak variables can have
constant initializers, but are never usable in constant expressions.