Fix Exp10M1(TSelf) and Round(TSelf, MidpointRounding)

[blokyk]

IExponentialFunctions.Exp10M1 had a typo that caused it to go into infinite recursion, and IFloatingPoint.Round straight up just ignored it's mode argument, most likely just a typo again.

Fixes #75059

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Issue Details

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IExponentialFunctions.Exp10M1 had a type that caused it to go into infinite recursion, and IFloatingPoint.Round straight up just ignored it's mode argument, most likely just a typo again.

Fixes #75059

Author:	Blokyk
Assignees:	-
Labels:	area-System.Numerics
Milestone:	-

[blokyk]

I apologize for the lack of tests -- I'm currently experiencing connectivity issues, which makes cloning and building the runtime a bit tricky. I'm writing some right now for both of the functions that I fixed, but if needed I can try to add more while I wait for my internet to come back. Sorry for submitting this PR without the tests first

[tannergooding]

I apologize for the lack of tests -- I'm currently experiencing connectivity issues, which makes cloning and building the runtime a bit tricky. I'm writing some right now for both of the functions that I fixed, but if needed I can try to add more while I wait for my internet to come back. Sorry for submitting this PR without the tests first

Absolutely no worries. We'd much rather have a fix up than not at all. Someone else can always pick it up and add tests if necessary/etc 😄

[tannergooding]

Changes LGTM. Just a few minor nits to use float instead of using Single

[dakersnar]

LGTM, and thanks for submitting unit tests too.

[tannergooding]

/backport to release/7.0

[github-actions]

Started backporting to release/7.0: https://github.com/dotnet/runtime/actions/runs/3016956207