[clang] [Clang][OpenCL][AMDGPU] Allow a kernel to call another kernel (PR #115821)

[Dmitry Sidorov via cfe-commits]

MrSidims wrote:

> this change makes sense and it doesn't bring (known to me) regressions

Actually, there is an incorrect behavior in the following test case: https://godbolt.org/z/dc3T7Mo3G , note __clang_ocl_kern_imp_sample_kernel_float was generated, but was never called. @lalaniket8 can this be addressed? 
 

https://github.com/llvm/llvm-project/pull/115821