devel/llvm16: merge backports from FreeBSD src

These upstream LLVM commits have been merged to FreeBSD's source tree
post the 17.0.6 release:

7440e4ed85aa [sanitizer] Add re-execution on FreeBSD when ASLR is detected (#73439)
989879f8fded [Clang] Allow C++11 style initialisation of SVE types.
9ca395b5ade1 [clang][AST] Propagate the contains-errors bit to DeclRefExpr from VarDecl's initializer.

While here, be consistant about using 12 digits of commit hash.