[NFC][DebugInfo] Make some block-start-position methods return iterators (#124287)

As part of the "RemoveDIs" work to eliminate debug intrinsics, we're
replacing methods that use Instruction*'s as positions with iterators. A
number of these (such as getFirstNonPHIOrDbg) are sufficiently
infrequently used that we can just replace the pointer-returning version
with an iterator-returning version, hopefully without much/any
disruption.

Thus this patch has getFirstNonPHIOrDbg and
getFirstNonPHIOrDbgOrLifetime return an iterator, and updates all
call-sites. There are no concerns about the iterators returned being
converted to Instruction*'s and losing the debug-info bit: because the
methods skip debug intrinsics, the iterator head bit is always false
anyway.

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp b/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp
index 4ff6fc32b642..df0c2080e079 100644
--- a/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp
+++ b/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp
@@ -232,7 +232,7 @@ Value *SIAnnotateControlFlow::handleLoopCondition(
     } else if (L->contains(Inst)) {
       Insert = Term;
     } else {
-      Insert = L->getHeader()->getFirstNonPHIOrDbgOrLifetime();
+      Insert = &*L->getHeader()->getFirstNonPHIOrDbgOrLifetime();
     }
 
     return CreateBreak(Insert);
@@ -247,7 +247,7 @@ Value *SIAnnotateControlFlow::handleLoopCondition(
   }
 
   if (isa<Argument>(Cond)) {
-    Instruction *Insert = L->getHeader()->getFirstNonPHIOrDbgOrLifetime();
+    Instruction *Insert = &*L->getHeader()->getFirstNonPHIOrDbgOrLifetime();
     return CreateBreak(Insert);
   }