Avx512: Abs, ceil, floor, min, max

[jkrishnavs]

Adding support for AVX 512:
Abs, ceil, floor, min, max, sqrt, Negate, and Unary Addition.

Covered cases:

1. Abs:
   Abs(Vector512), Abs(Vector512), Abs(Vector512), Abs(Vector512), Abs(Vector512)
   , Abs(Vector512)

2. ceil:
   ceil(Vector512), ceil(Vector512)

3. Floor:
   Floor(Vector512), Floor(Vector512)

4. Min
   Min(Vector512, Vector512), Min(Vector512, Vector512),
   Min(Vector512, Vector512), Min(Vector512, Vector512),
   Min(Vector512, Vector512), Min(Vector512, Vector512)

5. Max
   Max(Vector512, Vector512), Max(Vector512, Vector512),
   Max(Vector512, Vector512), Max(Vector512, Vector512),
   Max(Vector512, Vector512), Max(Vector512, Vector512)

6. Negate & Unary Addition:
   Negate(Vector512), Negate(Vector512), Negate(Vector512), Negate(Vector512), Negate(Vector512), Negate(Vector512)

Operator for Negate and Unary Addition.

Introduced a few new instructions that were not supported by lower vector intrinsics:

1. pabsq: Abs for long
2. min max for long

[tannergooding]

Resolved the merge conflict caused by other merged PRs

[tannergooding]

Changes LGTM. Just a couple minor code cleanup requests.

[tannergooding]

Actually, on second thought, remembered that there is still a need to fixup the roundps and roundpd instructions in instrsxarch.h as they are still marked as EVEX incompatible.

They do actually, in that they become the vrndscaleps/vrndscalepd instructions and the upper 4-bits of the immediate can now be non-zero.

That also means we probably need to update instr.cpp to ensure that roundps/roundpd are emitted as vrndscale in the disassembly

Without this fix, Ceiling and Floor are going to fail in their tests

-- The scalar versions, roundss and roundsd probably need the same treatment.

[jkrishnavs]

to update instr.cpp to ensure that roundps/roundpd are emitted as vrndscale in the disassembly

We have tried to add vrndscaleps/vrndscalepd instructions. hope this will find the round instruction

[tannergooding]

LGTM, thanks!

[jkrishnavs]

for some weird reason, git + was added to the code change. making an additional push to remove that.

[tannergooding]

CC. @dotnet/jit-contrib, @dotnet/avx512-contrib

this needs a secondary sign-off from the JIT side