Fix PR13052 properly, by performing special member lookup to determine whether
an explicitly-defaulted default constructor would be constexpr. This is
necessary in weird (but well-formed) cases where a class has more than one copy
or move constructor.

Cleanup of now-unused parts of CXXRecordDecl to follow.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@158289 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed