[LLVM-C] Deprecate the LLVMValueRef-returning metadata creation functions
Summary: There is still some value in using these functions while the remaining LLVMValueRef-based accessors are still around, but LLVMMDNodeInContext in particular has some wonky semantics that make it worth replacing outright.
Reviewers: whitequark, deadalnix
Reviewed By: whitequark
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D60524