[mlir] Don't elide the last op if there is no terminator

[antiagainst]

Fix another place

[mehdi_amini]

Do you have a test for that?

[antiagainst]

Add test

[antiagainst]

In D103264#2785248, @mehdi_amini wrote:

Do you have a test for that?

Added one.

mlir/lib/IR/AsmPrinter.cpp

if (printBlockArgs) {
         if (printerFlags.shouldPrintDebugInfo())
           // TODO: Allow deferring argument locations.
           initializer.visit(arg.getLoc(), /*canBeDeferred=*/false);
       }
     }
 
     // Consider the operations within this block, ignoring the terminator if
     // requested.
+    bool hasTerminator =
+        !block->empty() && block->back().hasTrait<OpTrait::IsTerminator>();
     auto range = llvm::make_range(
-        block->begin(), std::prev(block->end(), printBlockTerminator ? 0 : 1));
+        block->begin(),
+        std::prev(block->end(),
+                  !hasTerminator || printBlockTerminator ? 0 : 1));
     for (Operation &op : range)
       print(&op);
   }
 
   /// Print the given region.
   void printRegion(Region &region, bool printEntryBlockArgs,
                    bool printBlockTerminators,
                    bool printEmptyBlock = false) override {