BUILD: tools: fix warning about incorrect cast with dladdr1()

BUILD: tools: fix warning about incorrect cast with dladdr1()

dladdr1() is used on glibc and takes a void**, but we pass it a
const ElfW(Sym)** and some compilers complain that we're aliasing.
Let's just set a may_alias attribute on the local variable to
address this. There's no need to backport this unless warnings are
reported on older distros or uncommon compilers.