UpdateTestChecks: hexagon support

UpdateTestChecks: hexagon support

Summary:
These tests are being affected by an upcoming patch,
so having an understandable (autogenerated) diff is helpful.

This target, again, prefers `-march`:
```
llvm/test/CodeGen/Hexagon$ grep -r triple | wc -l
467
llvm/test/CodeGen/Hexagon$ grep -r march | wc -l
1167
```

Reviewers: RKSimon, kparzysz

Reviewed By: kparzysz

Subscribers: xbolva00, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62867

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362605 91177308-0d34-0410-b5e6-96231b3b80d8