Patch by Kit Barton.
Support for the ICBT instruction is currently present, but limited to
embedded processors. This change adds a new FeatureICBT that can be used
to identify whether the ICBT instruction is available on a specific processor.
Two new tests are added:
* Positive test to ensure the icbt instruction is present when using
-mcpu=pwr8
* Negative test to ensure the icbt instruction is not generated when
using -mcpu=pwr7
Both test cases use the Prefetch opcode in LLVM. They are based on the
ppc64-prefetch.ll test case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226033 91177308-0d34-0410-b5e6-96231b3b80d8
