[mlir][spirv] Allow complex element types in memref allocation checks (#175836)
Support for complex types in SPIR-V was introduced in
97f3bb73a29a566e99e33ae4338c2c3d9957e561, and memref type conversion was
updated accordingly to include them. However, the element type precheck
used during memref alloc/dealloc pattern matching in the SPIR-V lowering
was not updated to recognize complex element types. This patch resolves
this inconsistency.
Fixes: https://github.com/iree-org/iree/issues/23117
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Signed-off-by: Eric Feng <Eric.Feng@amd.com>