[llvm] [Analysis][EphemeralValuesAnalysis][NFCI] Remove EphemeralValuesCache class (PR #132454)

[Nikita Popov via llvm-commits]

nikic wrote:

This introduced a compile-time regression (unlike the original change): https://llvm-compile-time-tracker.com/compare.php?from=c0b2c10e9f3a939c227a26aec3ba377f7cc25667&to=4adefcfb856aa304b7b0a9de1eec1814f3820e83&stat=instructions:u

https://github.com/llvm/llvm-project/pull/132454