Add finalize method to modref summary.
gcc/ChangeLog:
* ipa-modref.c (modref_summary::global_memory_read_p): Remove.
(modref_summary::global_memory_written_p): Remove.
(modref_summary::dump): Dump new flags.
(modref_summary::finalize): New member function.
(analyze_function): Call it.
(read_section): Call it.
(update_signature): Call it.
(pass_ipa_modref::execute): Call it.
* ipa-modref.h (struct modref_summary): Remove
global_memory_read_p and global_memory_written_p.
Add global_memory_read, global_memory_written.
* tree-ssa-structalias.c (determine_global_memory_access):
Update.