[OpaquePtrs] Remove some uses of type-less CreateGEP() (NFC)

This removes some (but not all) uses of type-less CreateGEP()
and CreateInBoundsGEP() APIs, which are incompatible with opaque
pointers.

There are a still a number of tricky uses left, as well as many
more variation APIs for CreateGEP.

GitOrigin-RevId: 42eb658f656c43ee63e25222f32abbbbcb86ad7b
diff --git a/lib/CodeGen/RuntimeDebugBuilder.cpp b/lib/CodeGen/RuntimeDebugBuilder.cpp
index 2a349fe..d7d8348 100644
--- a/lib/CodeGen/RuntimeDebugBuilder.cpp
+++ b/lib/CodeGen/RuntimeDebugBuilder.cpp
@@ -188,7 +188,7 @@
   Value *Data = new AllocaInst(
       T, DL.getAllocaAddrSpace(), "polly.vprint.buffer",
       &Builder.GetInsertBlock()->getParent()->getEntryBlock().front());
-  auto *DataPtr = Builder.CreateGEP(Data, {Zero, Zero});
+  auto *DataPtr = Builder.CreateGEP(T, Data, {Zero, Zero});
 
   int Offset = 0;
   for (auto Val : ToPrint) {