[clang] [Clang] Fix CXXRewrittenBinaryOperator::getDecomposedForm to handle case when spaceship operator returns comparison category by reference (PR #66270)

[Timm Baeder via cfe-commits]

tbaederr wrote:

Ping @shafik, just needs a rebase :)

https://github.com/llvm/llvm-project/pull/66270