Documentation: Update docs for C++ lambdas to more accurately reflect
C++1y init-capture support, and to improve some Doxygen markup.


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@185469 91177308-0d34-0410-b5e6-96231b3b80d8
Redirect the output of a test to a temporary file to prevent messing up
the test environment.


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@185470 91177308-0d34-0410-b5e6-96231b3b80d8