[AMDGPU] Add missing cases for V_INDIRECT_REG_{READ/WRITE}_GPR_IDX and V/S_INDIRECT_REG_WRITE_MOVREL (#171835)
A buildbot failure in https://github.com/llvm/llvm-project/pull/170323
when expensive checks were used highlighted that some of these patterns
were missing.
This patch adds `V_INDIRECT_REG_{READ/WRITE}_GPR_IDX` and
`V/S_INDIRECT_REG_WRITE_MOVREL` for `V6` and `V7` vector sizes.