[NFC][DebugInfo] Use iterator moveBefore at many call-sites (#123583)

As part of the "RemoveDIs" project, BasicBlock::iterator now carries a
debug-info bit that's needed when getFirstNonPHI and similar feed into
instruction insertion positions. Call-sites where that's necessary were
updated a year ago; but to ensure some type safety however, we'd like to
have all calls to moveBefore use iterators.

This patch adds a (guaranteed dereferenceable) iterator-taking
moveBefore, and changes a bunch of call-sites where it's obviously safe
to change to use it by just calling getIterator() on an instruction
pointer. A follow-up patch will contain less-obviously-safe changes.

We'll eventually deprecate and remove the instruction-pointer
insertBefore, but not before adding concise documentation of what
considerations are needed (very few).

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp b/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
index b3883cd..5d5cbf9 100644
--- a/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
+++ b/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
@@ -1468,7 +1468,7 @@ static void hoistValue(Value *V, Instruction *HoistPoint, Region *R,
     for (Value *Op : I->operands()) {
       hoistValue(Op, HoistPoint, R, HoistStopMap, HoistedSet, TrivialPHIs, DT);
     }
-    I->moveBefore(HoistPoint);
+    I->moveBefore(HoistPoint->getIterator());
     HoistedSet.insert(I);
     CHR_DEBUG(dbgs() << "hoistValue " << *I << "\n");
   }