[SPIR-V] Invalid OpCopyLogical with identical operand and result types #9083

Description
Compiling a shader that copies a struct or array from a constant buffer into an RWStructuredBuffer can produce invalid SPIR-V when targeting SPIR-V 1.4 or later. This regressed in #7530: DXC emits OpCopyLogical to convert between buffer layouts, but when those layouts coincide, type lowering can deduplicate the source and destination into the same SPIR-V type.  OpCopyLogical requires distinct operand and result types, so validation fails with “Result Type must not equal the Operand type.” The fix emits OpCopyObject when the final type IDs match, retaining  OpCopyLogical  when they differ.

Steps to Reproduce
https://godbolt.org/z/PY6873GE7
Set the version back to 1.8.2505.1 and the compile will succeed

Actual Behavior
validation fails with “Result Type must not equal the Operand type.”

Environment

• DXC version 1.10.2605
• Host Operating System All