[mlir][spirv] Add conversion pass to rewrite splat constant composite… (#148910)
…s to replicated form
This adds a new SPIR-V dialect-level conversion pass
`ConversionToReplicatedConstantCompositePass`. This pass looks for splat
composite `spirv.Constant` or `spirv.SpecConstantComposite` and rewrites
them into `spirv.EXT.ConstantCompositeReplicate` or
`spirv.EXT.SpecConstantCompositeReplicate`, respectively.
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Signed-off-by: Mohammadreza Ameri Mahabadian <mohammadreza.amerimahabadian@arm.com>