Add support for handling captured variables in lambda debug info.
This currently doesn't handle capturing the 'this' pointer for any
enclosing class.

Steal the lambda-expressions.cpp testcase and debugify it and try
to use more variables to proof it against random changes.

Part of rdar://10900684

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@151702 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed