Many of these are simply upcast based implementations with some edge case handling, the ones with the license text at the top were ported from the rocm device library (hence the license text). Some of the upcast implementations here rely on builtins added by https://reviews.llvm.org/D134887, so this revision is based on those changes, and is intended to be merged after them.
Also removes code from generic files that was generating an ldexp fp16 declaration without an implementation.
This contribution is being made by Codeplay on behalf of Samsung.