Remove code that tries to avoid transforming non-dependent call operator types
for lambda expressions. That can't ever work; we need to transform the
parameters in order to create new ones in the new call operator context.

Fixes a rejects-valid when transforming a context containing a
lambda-expression that uses its function parameters in C++14 mode.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@222482 91177308-0d34-0410-b5e6-96231b3b80d8