[Coroutines] Enhance symmetric transfer for constant CmpInst

This fixes bug52896.

Simply, some symmetric transfer optimization chances get invalided due
to we delete some inlined optimization passes in 822b92aa. This would
cause stack-overflow in some situations which should be avoided by the
design of coroutine. This patch tries to fix this by transforming the
constant CmpInst instruction which was done in the deleted passes.

Reviewed By: rjmccall, junparser

Differential Revision: https://reviews.llvm.org/D116327