Replace individual operands GLC, SLC, and DLC with a single cache_policy
bitmask operand. This will reduce the number of operands in MIR and I hope
the amount of code. These operands are mostly 0 anyway.
Additional advantage that parser will accept these flags in any order unlike
now.
Differential Revision: https://reviews.llvm.org/D96469
There are a number of MIR tests using instructions on subtargets where
they don't really exist. These are some of the easy cases that don't
require splitting up test functions.
