[mlir][tosa] Add F32 to F16 type narrowing pass (#218900)
Add `tosa-narrow-f32-to-f16`, extending the shared TOSA type narrowing
infrastructure with support for destructively converting F32 tensors,
scalar attributes, dense constants, and resource-backed constants to
F16.
The pass supports conservative and aggressive rewriting, optional
function-boundary conversion, and optional preservation of F32
accumulator types.
Add coverage for constant precision loss, function boundaries, regions,
dense resources, aggressive rewriting, and accumulator-type
preservation.
Signed-off-by: Davide Grohmann <davide.grohmann@arm.com>
