[CUDA] Make lambdas inherit __host__ and __device__ attributes from the scope...

[CUDA] Make lambdas inherit __host__ and __device__ attributes from the scope in which they're created.

Summary: NVCC compat.  Fixes bug 30567.

Reviewers: tra

Subscribers: cfe-commits, rnk

Differential Revision: https://reviews.llvm.org/D25105

llvm-svn: 282880