NEON arch: dead ref cycle fix
NEON arch: dead ref cycle fix

When neon_available_ is ON, the DotProduct was set to point to DotProduct,
which should have been DotProductNative, as dotProduct is the *target* global itself:
see simddetect.h --> effectively making that part of the SetDotProduct() call
identical to this (no-op) statement: `DotProduct = DotProduct;`

Also added the Neon check in the Update() API, where it exists together
with the other checks (for AVX/SSE/etc.)

[sw: formatted commit message and merged into main branch]

Signed-off-by: Stefan Weil <8d4c780fcfdc41841e5070f4c43da8958ba6aec0@weilnetz.de>

stweil/tesseract,amitdo/tesseract,stweil/tesseract,amitdo/tesseract,UB-Mannheim/tesseract,amitdo/tesseract,tesseract-ocr/tesseract,tesseract-ocr/tesseract,UB-Mannheim/tesseract,amitdo/tesseract,stweil/tesseract,amitdo/tesseract,UB-Mannheim/tesseract,UB-Mannheim/tesseract,UB-Mannheim/tesseract,stweil/tesseract,tesseract-ocr/tesseract,tesseract-ocr/tesseract,tesseract-ocr/tesseract,stweil/tesseract