[llvm] [InferAddressSpaces] Handle unconverted ptrmask (PR #140802)

[Robert Imschweiler via llvm-commits]

================
@@ -495,6 +495,13 @@ class TargetTransformInfo {
 
   LLVM_ABI bool isNoopAddrSpaceCast(unsigned FromAS, unsigned ToAS) const;
 
+  LLVM_ABI std::pair<KnownBits, KnownBits>
+  computeKnownBitsAddrSpaceCast(unsigned FromAS, unsigned ToAS,
+                                const Value &PtrOp) const;
+
+  LLVM_ABI KnownBits computeKnownBitsAddrSpaceCast(
----------------
ro-i wrote:

I already replaced the zext by an anyext in a previous commit, so I don't assume anything specific about the casts afaics. Except that larger->smaller casts truncate. But that may be too much to assume, either.

https://github.com/llvm/llvm-project/pull/140802