[flang] [llvm] [mlir] [flang][OpenMP] Enable tiling (PR #143715)

[Sergio Afonso via llvm-commits]

================
@@ -3035,16 +3035,46 @@ convertOmpLoopNest(Operation &opInst, llvm::IRBuilderBase &builder,
     loopInfos.push_back(*loopResult);
   }
 
-  // Collapse loops. Store the insertion point because LoopInfos may get
-  // invalidated.
   llvm::OpenMPIRBuilder::InsertPointTy afterIP =
       loopInfos.front()->getAfterIP();
 
-  // Update the stack frame created for this loop to point to the resulting loop
-  // after applying transformations.
+  // Do tiling.
+  if (const auto &tiles = loopOp.getTileSizes()) {
+    llvm::Type *IVType = loopInfos.front()->getIndVarType();
----------------
skatrak wrote:

Nit: MLIR doesn't use uppercase first letter for variable names. Same comment for `TileSizes` and `TileVal`.
```suggestion
    llvm::Type *ivType = loopInfos.front()->getIndVarType();
```

https://github.com/llvm/llvm-project/pull/143715