[LLVM-C] Finish exception instruction bindings

Summary:
Add support for cleanupret, catchret, catchpad, cleanuppad and catchswitch and their associated accessors.

Test is modified from SimplifyCFG because it contains many diverse usages of these instructions.

Reviewers: whitequark, deadalnix, echristo

Reviewed By: echristo

Subscribers: llvm-commits, harlanhaskins

Differential Revision: https://reviews.llvm.org/D44496

llvm-svn: 328759