Replace unsigned with MCRegister at some of the call sites.

NVPTX, SPIRV, and WebAssembly pass virtual registers to this function
since they don't perform register allocation. We need to use Register to
avoid a virtual register being converted to MCRegister by the caller.

- Change InstrInfoEmitter to emit OpName as an enum class
  instead of an anonymous enum in the OpName namespace.
- This will help clearly distinguish between values that are 
  OpNames vs just operand indices and should help avoid
  bugs due to confusion between the two.
- Rename OpName::OPERAND_LAST to NUM_OPERAND_NAMES.
- Emit declaration of getOperandIdx() along with the OpName
  enum so it doesn't have to be repeated in various headers.
- Also updated AMDGPU, RISCV, and WebAssembly backends
  to conform to the new definition of OpName (mostly
  mechanical changes).

Identified with misc-include-cleaner.

The renamable flag is useful during MachineCopyPropagation but renamable
flag will be dropped after lowerCopy in some case.

This patch introduces extra arguments to pass the renamable flag to
copyPhysReg.

MachineRegisterInfo::liveins returns std::pair<MCRegister, Register>.
Don't convert to std::pair<unsigned, unsigned>.

Fixes #82659

There are some functions, such as `findRegisterDefOperandIdx` and  `findRegisterDefOperand`, that have too many default parameters. As a result, we have encountered some issues due to the lack of TRI  parameters, as shown in issue #82411.

Following @RKSimon 's suggestion, this patch refactors 9 functions, including `{reads, kills, defines, modifies}Register`,  `registerDefIsDead`, and `findRegister{UseOperandIdx, UseOperand, DefOperandIdx, DefOperand}`, adjusting the order of the TRI parameter and making it required. In addition, all the places that call these functions have also been updated correctly to ensure no additional impact.

After this, the caller of these functions should explicitly know whether to pass the `TargetRegisterInfo` or just a `nullptr`.