Rearrange narrowing checks in initialization to be a different form of step
rather than a post-processing action, so we can support inserting these checks
at stages other than the end of the initialization. No functionality change
intended.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@191146 91177308-0d34-0410-b5e6-96231b3b80d8
Some comment updates and tweaks for clarity.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@191147 91177308-0d34-0410-b5e6-96231b3b80d8
PR17295: Do not allow explicit conversion functions to be used in cases where
an additional conversion (other than a qualification conversion) would be
required after the explicit conversion.

Conversely, do allow explicit conversion functions to be used when initializing
a temporary for a reference binding in direct-list-initialization.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@191150 91177308-0d34-0410-b5e6-96231b3b80d8