CodeGen: Fix handling of C++11 lambdas in profiling

Until now we were generating duplicate counters for lambdas: one set
in the function where the lambda was declared and another for the
lambda itself. Instead, we should skip over the bodies of lambdas in
their containing contexts.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@206081 91177308-0d34-0410-b5e6-96231b3b80d8