Fix C++ ForEach reflection (bad usrData args).

This fixes issues with the following areas:
1) usrData arguments to kernels.
2) set vs. bind for export variables.
3) improved argument handling for kernels/invoke.

Bug: 5972398
Change-Id: I09a7b9198c45ab6e2d10b2abae1727ee0e559736
6 files changed