[clang] [llvm] [Clang][IR] add TBAA metadata on pointer, union and array types. (PR #75177)

[Bushev Dmitry via llvm-commits]

================
@@ -184,13 +205,59 @@ llvm::MDNode *CodeGenTBAA::getTypeInfoHelper(const Type *Ty) {
     return getChar();
 
   // Handle pointers and references.
-  // TODO: Implement C++'s type "similarity" and consider dis-"similar"
-  // pointers distinct.
-  if (Ty->isPointerType() || Ty->isReferenceType())
-    return createScalarTypeNode("any pointer", getChar(), Size);
+  //
+  // In C11 for two pointer type to alias it is required for them to be
+  // compatible [section 6.5 p7].
----------------
dybv-sc wrote:

Great idea! Thanks for help with it. Added those comments.

https://github.com/llvm/llvm-project/pull/75177