Check kernels before fusing

b/21958851

Kernel fusion for a Script Group expects kernels to be chained up
via outputs (return values) and first arguments.
Check this condition during fusion. Otherwise, BCC may crash on
broken invariants.

Change-Id: I013558c77dc3f79d6e42986121927dd6c695f27e
(cherry picked from commit 8c12d615b4ed4b1d782722a125dd1d43bc44a71b)
2 files changed