Add some tests for cast+clamp/min/max before D33186.

Summary:
- add more tests
- pr27236.ll: rename %tmpN -> %N because otherwise a FileCheck
  variable for newly appeared unnamed value would use the same name as
  tmpN (as generated by update_test_checks.py)
- run update_test_checks.py

Reviewers: efriedma

Reviewed By: efriedma

Subscribers: n.bozhenov, llvm-commits

Patch by Andrei Elovikov <andrei.elovikov@intel.com>

Differential Revision: https://reviews.llvm.org/D35002

llvm-svn: 310053