Fix llvm-objcopy to add .note sections as SHT_NOTEs. GNU objcopy overrides section flags for special sections. For .note sections (with the exception of .note.GNU-stack), SHT_NOTE is used.
Many other sections are special cased by libbfd, but .note is the only special section I can seem to find being used with objcopy --add-section.
See .note in context of the full list of special sections here: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob;f=bfd/elf.c;h=eb3e1828e9c651678b95a1dcbc3b124783d1d2be;hb=HEAD#l2675