[llvm] [TTI] Support scalable offsets in getScalingFactorCost (PR #88113)

[Graham Hunter via llvm-commits]

================
@@ -32,6 +32,8 @@ class Function;
 /// Base class for use as a mix-in that aids implementing
 /// a TargetTransformInfo-compatible class.
 class TargetTransformInfoImplBase {
+  friend class TargetTransformInfo;
----------------
huntergr-arm wrote:

It's a leftover from a previous attempt at making an overloaded method to call the existing fixed-only method from the base implementation if there wasn't an override of the newer method. It didn't work out, so I've removed it. Thanks for spotting it.

https://github.com/llvm/llvm-project/pull/88113