Fix crash with cast of value-dependent expr.

We don't really need to perform semantic analysis on the dependent expression
anyway, so just call the cast dependent.

<rdar://problem/15012610>

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@190981 91177308-0d34-0410-b5e6-96231b3b80d8
Use curly braces all the way through long if/else chain for consistency and readability.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@190982 91177308-0d34-0410-b5e6-96231b3b80d8