The PR reports that building with -Wodr -flto complains about different
versions of struct ipa_sym_addresses, in common/agent.c and
gdbserver/tracepoint.c. This patch renames the version in common to
ipa_sym_addresses_common to avoid the name clash. Because the IPA_SYM
assumed the name ipa_sym_addresses, it now requires the includer to
define the IPA_SYM_STRUCT_NAME macro to define the name of the structure
holding the IPA symbol addresses.