[NFC][RemoveDIs] Use iterators over inst-pointers when using IRBuilder

This patch adds a two-argument SetInsertPoint method to IRBuilder that
takes a block/iterator instead of an instruction, and updates many call
sites to use it. The motivating reason for doing this is given here [0],
we'd like to pass around more information about the position of debug-info
in the iterator object. That necessitates passing iterators around most of
the time.

[0] https://discourse.llvm.org/t/rfc-instruction-api-changes-needed-to-eliminate-debug-intrinsics-from-ir/68939

Differential Revision: https://reviews.llvm.org/D152468

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index 3bfcb566a807..f07fc4fc52bf 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -2263,7 +2263,7 @@ static bool despeculateCountZeros(IntrinsicInst *CountZeros,
 
   // Create a PHI in the end block to select either the output of the intrinsic
   // or the bit width of the operand.
-  Builder.SetInsertPoint(&EndBlock->front());
+  Builder.SetInsertPoint(EndBlock, EndBlock->begin());
   PHINode *PN = Builder.CreatePHI(Ty, 2, "ctz");
   replaceAllUsesWith(CountZeros, PN, FreshBBs, IsHugeFunc);
   Value *BitWidth = Builder.getInt(APInt(SizeInBits, SizeInBits));