Use enums for the strict flex arrays flag so that it's more readable.
Thanks for working on this! A few nits inline
I think you meant Any trailing array member of undefined size is a FAM
Note that this depends on https://reviews.llvm.org/D134902 to have the "Incomplete" support.
The StaticAnalyzer changes seem to be correct.
For most cases, I can either see no initializers or only the first entry is being initialized.