[mlir][TosaToLinalg] Ensure valid insertion pointer after op erasure (#146908)

Erasing/replacing an op, which is also the current insertion point,
invalidates the insertion point. Explicitly set the insertion point, so
that subsequent op insertions do not crash after the One-Shot Dialect
Conversion refactoring. (`ConversionPatternRewriter` will start behaving
more like a "normal" rewriter.)

Author: matthias-springer

mlir/lib/Conversion/TosaToLinalg/TosaToLinalgNamed.cpp

@@ -807,6 +807,7 @@ class MaxPool2dConverter : public OpConversionPattern<tosa::MaxPool2dOp> {
         ValueRange{paddedInput, fakeWindowDims}, filledEmptyTensor, strideAttr,
         dilationAttr);
 
+    rewriter.setInsertionPointAfter(op);
     rewriter.replaceOp(op, resultOp);
 
     // NaN propagation has no meaning for non floating point types.