This pull request fixes MSVC compiler warnings by adding appropriate casts in the following areas:

1. Added for array index conversions in avx2-emu-funcs.hpp
2. Added for 16-bit constants like 0x8000 and 0x7c00 in avx512-16bit-qsort.hpp
3. Replaced with 0 for the intrinsic to fix out of range warning
4. Added when passing uint64_t values to functions expecting int32_t
5. Added for double to int conversions in xss-common-keyvaluesort.hpp

These changes resolve MSVC compiler warnings C4244 (conversion with potential data loss), C4309 (truncation of constant value), and C4556 (value of intrinsic immediate argument out of range).

Note: The warnings about 'getenv' being unsafe were intentionally not addressed as it would require platform-specific handling.