Build warnings with MSVC

[r-devulap]

When building with MSVC, these warnings show up. Might be useful to fix them.

[1/8] Compiling C++ object x86simdsortcpp-1.dll.p/lib_x86simdsort.cpp.obj
../lib/x86simdsort.cpp(16): warning C4996: 'getenv': This function or variable may be unsafe. Consider using _dupenv_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.
[2/8] Compiling C++ object lib/liblibicl.a.p/x86simdsort-icl.cpp.obj
C:\Users\merag\source\repos\x86-simd-sort\src\avx2-emu-funcs.hpp(150): warning C4244: 'argument': conversion from 'uint64_t' to 'std::array<std::array<int32_t,8>,256>::size_type', possible loss of data
..\src\avx512-16bit-qsort.hpp(52): warning C4309: 'argument': truncation of constant value
..\src\avx512-16bit-qsort.hpp(53): warning C4309: 'argument': truncation of constant value
..\src\avx512-16bit-qsort.hpp(65): warning C4309: 'argument': truncation of constant value
..\src\avx512-16bit-qsort.hpp(139): warning C4556: value of intrinsic immediate argument '8' is out of range '0 - 7'
[4/8] Compiling C++ object lib/liblibavx.a.p/x86simdsort-avx2.cpp.obj
C:\Users\merag\source\repos\x86-simd-sort\src\avx2-emu-funcs.hpp(150): warning C4244: 'argument': conversion from 'uint64_t' to 'std::array<std::array<int32_t,8>,256>::size_type', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\avx2-32bit-half.hpp(45): warning C4244: 'argument': conversion from 'unsigned __int64' to 'int32_t', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\avx2-32bit-half.hpp(49): warning C4244: 'argument': conversion from 'uint64_t' to 'int32_t', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\avx2-32bit-half.hpp(212): warning C4244: 'argument': conversion from 'unsigned __int64' to 'int32_t', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\avx2-32bit-half.hpp(216): warning C4244: 'argument': conversion from 'uint64_t' to 'int32_t', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\avx2-32bit-half.hpp(390): warning C4244: 'argument': conversion from 'unsigned __int64' to 'int32_t', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\avx2-32bit-half.hpp(394): warning C4244: 'argument': conversion from 'uint64_t' to 'int32_t', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\avx2-64bit-qsort.hpp(56): warning C4244: 'argument': conversion from 'unsigned __int64' to 'int32_t', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\avx2-64bit-qsort.hpp(60): warning C4244: 'argument': conversion from 'uint64_t' to 'int32_t', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\avx2-64bit-qsort.hpp(244): warning C4244: 'argument': conversion from 'unsigned __int64' to 'int32_t', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\avx2-64bit-qsort.hpp(248): warning C4244: 'argument': conversion from 'uint64_t' to 'int32_t', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\avx2-64bit-qsort.hpp(442): warning C4244: 'argument': conversion from 'unsigned __int64' to 'int32_t', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\avx2-64bit-qsort.hpp(446): warning C4244: 'argument': conversion from 'uint64_t' to 'int32_t', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\xss-common-keyvaluesort.hpp(591): warning C4244: 'initializing': conversion from 'double' to 'int', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\xss-common-keyvaluesort.hpp(591): note: the template instantiation context (the oldest one first) is
../lib/x86simdsort-avx2.cpp(87): note: see reference to function template instantiation 'void x86simdsortStatic::keyvalue_qsort<uint64_t,uint64_t>(T1 *,T2 *,size_t,bool,bool)' being compiled
        with
        [
            T1=uint64_t,
            T2=uint64_t
        ]
..\src\x86simdsort-static-incl.h(208): note: see reference to function template instantiation 'void avx2_qsort_kv<T1,T2>(T1 *,T2 *,arrsize_t,bool,bool)' being compiled
        with
        [
            T1=uint64_t,
            T2=uint64_t
        ]
C:\Users\merag\source\repos\x86-simd-sort\src\xss-common-keyvaluesort.hpp(758): note: see reference to function template instantiation 'void xss_qsort_kv<T1,T2,avx2_vector,avx2_half_vector>(T1 *,T2 *,arrsize_t,bool,bool)' being compiled
        with
        [
            T1=uint64_t,
            T2=uint64_t
        ]
C:\Users\merag\source\repos\x86-simd-sort\src\xss-common-keyvaluesort.hpp(686): warning C4244: 'initializing': conversion from 'double' to 'int', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\xss-common-keyvaluesort.hpp(686): note: the template instantiation context (the oldest one first) is
../lib/x86simdsort-avx2.cpp(87): note: see reference to function template instantiation 'void x86simdsortStatic::keyvalue_select<uint64_t,uint64_t>(T1 *,T2 *,size_t,size_t,bool,bool)' being compiled
        with
        [
            T1=uint64_t,
            T2=uint64_t
        ]
..\src\x86simdsort-static-incl.h(208): note: see reference to function template instantiation 'void avx2_select_kv<T1,T2>(T1 *,T2 *,arrsize_t,arrsize_t,bool,bool)' being compiled
        with
        [
            T1=uint64_t,
            T2=uint64_t
        ]
C:\Users\merag\source\repos\x86-simd-sort\src\xss-common-keyvaluesort.hpp(782): note: see reference to function template instantiation 'void xss_select_kv<T1,T2,avx2_vector,avx2_half_vector>(T1 *,T2 *,arrsize_t,arrsize_t,bool,bool)' being compiled
        with
        [
            T1=uint64_t,
            T2=uint64_t
        ]
[6/8] Compiling C++ object lib/liblibskx.a.p/x86simdsort-skx.cpp.obj
C:\Users\merag\source\repos\x86-simd-sort\src\avx2-emu-funcs.hpp(150): warning C4244: 'argument': conversion from 'uint64_t' to 'std::array<std::array<int32_t,8>,256>::size_type', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\xss-common-keyvaluesort.hpp(591): warning C4244: 'initializing': conversion from 'double' to 'int', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\xss-common-keyvaluesort.hpp(591): note: the template instantiation context (the oldest one first) is
../lib/x86simdsort-skx.cpp(87): note: see reference to function template instantiation 'void x86simdsortStatic::keyvalue_qsort<uint64_t,uint64_t>(T1 *,T2 *,size_t,bool,bool)' being compiled
        with
        [
            T1=uint64_t,
            T2=uint64_t
        ]
..\src\x86simdsort-static-incl.h(174): note: see reference to function template instantiation 'void avx512_qsort_kv<T1,T2>(T1 *,T2 *,arrsize_t,bool,bool)' being compiled
        with
        [
            T1=uint64_t,
            T2=uint64_t
        ]
C:\Users\merag\source\repos\x86-simd-sort\src\xss-common-keyvaluesort.hpp(747): note: see reference to function template instantiation 'void xss_qsort_kv<T1,T2,zmm_vector,ymm_vector>(T1 *,T2 *,arrsize_t,bool,bool)' being compiled
        with
        [
            T1=uint64_t,
            T2=uint64_t
        ]
C:\Users\merag\source\repos\x86-simd-sort\src\xss-common-keyvaluesort.hpp(686): warning C4244: 'initializing': conversion from 'double' to 'int', possible loss of data
C:\Users\merag\source\repos\x86-simd-sort\src\xss-common-keyvaluesort.hpp(686): note: the template instantiation context (the oldest one first) is
../lib/x86simdsort-skx.cpp(87): note: see reference to function template instantiation 'void x86simdsortStatic::keyvalue_select<uint64_t,uint64_t>(T1 *,T2 *,size_t,size_t,bool,bool)' being compiled
        with
        [
            T1=uint64_t,
            T2=uint64_t
        ]
..\src\x86simdsort-static-incl.h(174): note: see reference to function template instantiation 'void avx512_select_kv<T1,T2>(T1 *,T2 *,arrsize_t,arrsize_t,bool,bool)' being compiled
        with
        [
            T1=uint64_t,
            T2=uint64_t
        ]
C:\Users\merag\source\repos\x86-simd-sort\src\xss-common-keyvaluesort.hpp(770): note: see reference to function template instantiation 'void xss_select_kv<T1,T2,zmm_vector,ymm_vector>(T1 *,T2 *,arrsize_t,arrsize_t,bool,bool)' being compiled
        with
        [
            T1=uint64_t,
            T2=uint64_t
        ]