Remove some non-unicode characters from source code (#39527)

Remove some non-unicode characters from source code (#39527)

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I've been noticing some C compiler warnings during build of dotnet/runtime.
```
  C:\Users\gotos\source\repos\runtime\src\mono\mono\mini\mini-runtime.c(1920,1): warning C4819: The file contains a character that cannot be represented in the current code page (949). Save the file in Unicode format to prevent data loss [C:\Users\gotos\source\repos\runtime\src\mono\msvc\libmono-dynamic.vcxproj]
  C:\Users\gotos\source\repos\runtime\src\mono\mono\mini\method-to-ir.c(5337,1): warning C4819: The file contains a character that cannot be represented in the current code page (949). Save the file in Unicode format to prevent data loss [C:\Users\gotos\source\repos\runtime\src\mono\msvc\libmono-dynamic.vcxproj]
```
Apparently there are some smart quotes and a zero-width space (Why?!) in some of Mono's source code. This PR removes those needless unicode characters.

I hope that opening a PR here will result in the changed code being mirrored to dotnet/runtime repo as well?

Co-authored-by: Gnbrkm41 <Gnbrkm41@users.noreply.github.com>