[llvm] Update callers of isTriviallyReMaterializable to check trivialness (PR #160319)

[Philip Reames via llvm-commits]

preames wrote:

Warning to anyone looking at this later, the landed version contained a nasty bug where I'd accidentally reversed the condition being checked for.  This was (accidentally) undone in https://github.com/llvm/llvm-project/pull/160377 but results in this change descriptions being super misleading.  Sorry!

https://github.com/llvm/llvm-project/pull/160319