[mlir] Avoid unnecessary copies in SCF's OneToNTypeConversions. (NFC)

[ingomueller-net]

Summary

In two places, a ResultRange was copied into a SmallVector just to be
passed as a ValueRange argument. With this patch, the ResultRanges are
passed directly, avoiding a copy.

[ingomueller-net]

Trivial NFC change. Will self-accept when CI passed.

@sabauma: Thanks for fixing this in your code -- that made me realize I could do the same ;)

mlir/lib/Dialect/SCF/Transforms/OneToNTypeConversion.cpp

matchAndRewrite(IfOp op, OpAdaptor adaptor,
     rewriter.eraseBlock(newOp.thenBlock());
 
     // Inlines block from the original operation.
     rewriter.inlineRegionBefore(op.getThenRegion(), newOp.getThenRegion(),
                                 newOp.getThenRegion().end());
     rewriter.inlineRegionBefore(op.getElseRegion(), newOp.getElseRegion(),
                                 newOp.getElseRegion().end());
 
-    rewriter.replaceOp(op, SmallVector<Value>(newOp->getResults()),
-                       resultMapping);
+    rewriter.replaceOp(op, newOp->getResults(), resultMapping);
     return success();
   }
 };
 
 class ConvertTypesInSCFWhileOp : public OneToNOpConversionPattern<WhileOp> {
 public:
   using OneToNOpConversionPattern<WhileOp>::OneToNOpConversionPattern;
 
for (unsigned int i : {0u, 1u}) {
 
       rewriter.applySignatureConversion(block, blockMappings[i]);
 
       // Move updated region to new WhileOp.
       Region &dstRegion = newOp.getRegion(i);
       rewriter.inlineRegionBefore(op.getRegion(i), dstRegion, dstRegion.end());
     }
 
-    rewriter.replaceOp(op, SmallVector<Value>(newOp->getResults()),
-                       resultMapping);
+    rewriter.replaceOp(op, newOp->getResults(), resultMapping);
     return success();
   }
 };
 
 class ConvertTypesInSCFYieldOp : public OneToNOpConversionPattern<YieldOp> {
 public:
   using OneToNOpConversionPattern<YieldOp>::OneToNOpConversionPattern;