CLR was designed to be able to support multiple kinds of languages, including C and C++.
At the release event there were about 40 languages being supported by multiple vendors.
The SDK being offered across multiple developer magazines had samples for several languages.
CLR was born from Ext-VOS project, formelly known as COM Runtime, the idea being that Windows would eventually be fully .NET based.
The idea never came to be, because .NET belongs to DevTools and Windows team was never happy with it.
The biggest example being the sabotage during Longhorn development and how the Phoenix, Singularity and Midori projects were received by them.
Also CLR always had the option of AOT compilation.
Initially via NGEN, Bartok in Singularity later adopted in Windows 8 for store apps, Project N from Midori later .NET Native for UWP apps.