[OpenCL] Add std flag aliases clc++1.0 and CLC++1.0

Renamed language standard from openclcpp to openclcpp10.
Added new std values i.e. '-cl-std=clc++1.0' and
'-cl-std=CLC++1.0'.

Patch by Topotuna (Justas Janickas)!

Differential Revision: https://reviews.llvm.org/D106266