Revert "[Hexagon] Start using regmasks on calls"

This reverts commit r295371.

It broke windows bots:

http://bb.pgr.jp/builders/ninja-clang-i686-msc19-R/builds/11402/steps/test-llvm/logs/stdio

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295402 91177308-0d34-0410-b5e6-96231b3b80d8
20 files changed