OSV-2020-868 Use-of-uninitialized-value in fetchARGB32ToRGBA64PM_avx2

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=21808 Crash type: Use-of-uninitialized-value Crash state: fetchARGB32ToRGBA64PMavx2 blenduntransformedgenericrgb64 fillRectnormalized...