[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/Utils/CloneFunction.cpp b/llvm/lib/Transforms/Utils/CloneFunction.cpp
index 127e7e6..58d400a 100644
--- a/llvm/lib/Transforms/Utils/CloneFunction.cpp
+++ b/llvm/lib/Transforms/Utils/CloneFunction.cpp
@@ -1144,7 +1144,7 @@ BasicBlock *llvm::DuplicateInstructionsInSplitBetween(
   for (; StopAt != &*BI && BB->getTerminator() != &*BI; ++BI) {
     Instruction *New = BI->clone();
     New->setName(BI->getName());
-    New->insertBefore(NewTerm);
+    New->insertBefore(NewTerm->getIterator());
     New->cloneDebugInfoFrom(&*BI);
     ValueMapping[&*BI] = New;