Removing the Sse2.LoadScalarVector128 overloads that are invalid.

[tannergooding]

FYI. @CarolEidt, @fiigii, @eerhardt.

These being added was an oversight, as per the discussion here: #16192 (comment)

These intrinsics do not have a corresponding instruction to emit and should not be simulated by the runtime.

[tannergooding]

Also FYI. @4creators, since you are working on the SSE2 ISA.

[fiigii]

Thank you!

[CarolEidt]

LGTM

[tannergooding]

Resolved merge conflicts.

[eerhardt]

Looks good. Thanks @tannergooding

[BruceForstall]

@tannergooding Don't you need to also remove them from the reference assembly https://github.com/dotnet/corefx/blob/master/src/System.Runtime.Intrinsics/ref/System.Runtime.Intrinsics.cs? I'm getting build breaks building corefx:

D:\j\workspace\x64_checked_w---a7bd363e\_\fx\Tools\ApiCompat.targets(54,5): error : MembersMustExist : Member 'System.Runtime.Intrinsics.X86.Sse2.LoadScalarVector128(System.Byte*)' does not exist in the implementation but it does exist in the contract. [D:\j\workspace\x64_checked_w---a7bd363e\_\fx\src\System.Runtime.Intrinsics\src\System.Runtime.Intrinsics.csproj]
D:\j\workspace\x64_checked_w---a7bd363e\_\fx\Tools\ApiCompat.targets(54,5): error : MembersMustExist : Member 'System.Runtime.Intrinsics.X86.Sse2.LoadScalarVector128(System.Int16*)' does not exist in the implementation but it does exist in the contract. [D:\j\workspace\x64_checked_w---a7bd363e\_\fx\src\System.Runtime.Intrinsics\src\System.Runtime.Intrinsics.csproj]
D:\j\workspace\x64_checked_w---a7bd363e\_\fx\Tools\ApiCompat.targets(54,5): error : MembersMustExist : Member 'System.Runtime.Intrinsics.X86.Sse2.LoadScalarVector128(System.SByte*)' does not exist in the implementation but it does exist in the contract. [D:\j\workspace\x64_checked_w---a7bd363e\_\fx\src\System.Runtime.Intrinsics\src\System.Runtime.Intrinsics.csproj]
D:\j\workspace\x64_checked_w---a7bd363e\_\fx\Tools\ApiCompat.targets(54,5): error : MembersMustExist : Member 'System.Runtime.Intrinsics.X86.Sse2.LoadScalarVector128(System.UInt16*)' does not exist in the implementation but it does exist in the contract. [D:\j\workspace\x64_checked_w---a7bd363e\_\fx\src\System.Runtime.Intrinsics\src\System.Runtime.Intrinsics.csproj]
D:\j\workspace\x64_checked_w---a7bd363e\_\fx\Tools\ApiCompat.targets(68,5): error : ApiCompat failed for 'D:\j\workspace\x64_checked_w---

e.g., https://ci.dot.net/job/dotnet_coreclr/job/master/job/jitstress/job/x64_checked_windows_nt_corefx_baseline/422/

[tannergooding]

Yes, I was waiting for the CoreFX PR that consumes this change to go up (there hasn't been a PR by dotnet-maestro-bot for me to update yet).

[tannergooding]

Actually, it looks like API removal (unlike addition or modification) doesn't require CoreCLR to be pumped back first. I've opened: dotnet/corefx#26933