[llvm] [VPlan] Migrate VPBuilder to VPInsertPt fully (NFC) (PR #209764)

[Florian Hahn via llvm-commits]

================
@@ -117,87 +154,44 @@ class VPBuilder {
 
 public:
   VPlan &getPlan() const {
-    assert(getInsertBlock() && "Insert block must be set");
-    return *getInsertBlock()->getPlan();
+    assert(InsertPt && "Insert block must be set");
+    return *InsertPt.getBlock()->getPlan();
   }
 
   VPBuilder() = default;
-  VPBuilder(VPBasicBlock *InsertBB) { setInsertPoint(InsertBB); }
-  VPBuilder(VPRecipeBase *InsertPt) { setInsertPoint(InsertPt); }
-  VPBuilder(VPBasicBlock *TheBB, VPBasicBlock::iterator IP) {
-    setInsertPoint(TheBB, IP);
-  }
-
-  /// Clear the insertion point: created instructions will not be inserted into
-  /// a block.
-  void clearInsertionPoint() {
-    BB = nullptr;
-    InsertPt = VPBasicBlock::iterator();
-  }
+  VPBuilder(const VPInsertPoint &IP) : InsertPt(IP) {}
+  VPBuilder(VPBasicBlock *TheBB, VPBasicBlock::iterator IP)
+      : InsertPt(TheBB, IP) {}
 
-  VPBasicBlock *getInsertBlock() const { return BB; }
-  VPBasicBlock::iterator getInsertPoint() const { return InsertPt; }
+  /// Get the recipe at the current point.
+  VPRecipeBase *getRecipe() const { return InsertPt; }
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fhahn wrote:

Would probably be good to clarify this returns the recipe at the insert point

```suggestion
  /// Get the recipe at the current insert point or nullptr if the insert point is the end of the block.
  VPRecipeBase *getRecipeAtInsertPoint() const { return InsertPt; }
```

https://github.com/llvm/llvm-project/pull/209764