Is there any way to view Xcode's arm64 compiler output in the form of assembly language, either using Xcode, the command-line developer tools that come bundled with Xcode, other developer tools from Apple, or some 3rd party utility?
(Since no one else answered, I'll post what I ended up with...)
Using the command-line tools that came with the released (Mac App store) Xcode installation:
clang -arch arm64 -I /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/include -S my_source_file.c
produced an .s file containing arm64 assembly language.