### whats the problem
mlir-opt could crash while verifying amdgpu.dpp when its operands had
vector
types, such as ARM SME tile vectors produced by arm_sme.get_tile.
The crash occurred during IR verification, before any lowering or passes
ran.
### why it happens
DPPOp::verify() called Type::getIntOrFloatBitWidth() on the operand
type.
When the operand was a VectorType, this hit an assertion because only
scalar
integer and float types have a bitwidth.
### whats the fix
Query the bitwidth on the element type using getElementTypeOrSelf()
instead of
the container type.
Add a regression test to ensure amdgpu.dpp verification no longer
asserts on
vector operand types.
Fixes#178128
c381180536