llvm-profgen gives error message when the input binary contains premature terminator in .debug_aranges section. These zero length items point to some rodata with zero size type in embed Rust Library. Considering Zero-Sized Types are a valid feature in Rust. They are not real error. This change makes the "error:" message into a warning to avoid misleading.
Why do we still want a warning on such case? because it doesn't follow dwarf standard. https://bugs.llvm.org/show_bug.cgi?id=46805 contains early discussion.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D124121
