buildtools/check-experimental-syms.sh assumes `objdump`, which will use whatever host system objdump is found in the default PATH. Cross-compiling requires this to take a prefix, eg `"${CROSS}"objdump`.
The objdump is only used in check-experimental-syms.sh which is called on compile time. While cross-compiling, any compile-time error does not occur even-though objdump is being used on ARM aarch64 architecture file because objdump is being used with -t flag which displays the symbol table only. With -t flag objdump does not give any error even if the object file is of different architecture. So, in conclusion, it does not matter if architecture specific objdump is used or not, the output will be the same for all architectures. I think we can close this bug.