[HLSL] add sqrt library function

This change exposes the sqrt library function for HLSL scalar types,
excluding long and long long doubles. Sqrt is supported for all scalar, vector,
and matrix types. This patch only adds a subset of scalar type support.

Long and long long double support is missing in this patch because that type
doesn't exist in HLSL.

The full documentation of the HLSL asin function is available here:
https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-sqrt

Reviewed By: beanz

Differential Revision: https://reviews.llvm.org/D132711