Delete SingleGetHashCode and DoubleGetHashCode tests for arm/arm64

[BruceForstall]

The tests themselves were deleted with #16567.

[BruceForstall]

cc @dotnet/arm32-contrib @dotnet/arm64-contrib

[BruceForstall]

Also delete StringCompare tests deleted with #16571

[sdmaclea]

Is there a reason we have to manually manage these lists for Arm64. Can the test list be updated automatically? At test runtime?

[BruceForstall]

We could probably auto-create the lists with some automation -- @jashook has some automation to update them, but it hasn't been used in a while.

Ideally, we would create a single cross-platform test infrastructure so we wouldn't have all three (or more?) msbuild/xunit, runtest.sh, and smarty.

[BruceForstall]

@dotnet-bot test Windows_NT arm Cross Checked normal Build and Test
@dotnet-bot test Windows_NT arm64 Cross Checked normal Build and Test

[BruceForstall]

@dotnet-bot test Windows_NT arm Cross Checked normal Build and Test
@dotnet-bot test Windows_NT arm64 Cross Checked normal Build and Test

[BruceForstall]

@dotnet-bot test Windows_NT arm Cross Checked normal Build and Test
@dotnet-bot test Windows_NT arm64 Cross Checked normal Build and Test

test Windows_NT armlb Cross Checked Innerloop Build and Test
test OSX10.12 x64 Checked Innerloop Build and Test