* arm.cc (Scan::local_reloc_may_be_function_pointer): New function.
(Scan::global_reloc_may_be_function_pointer): New function.
* sparc.cc (Scan::local_reloc_may_be_function_pointer): New function.
(Scan::global_reloc_may_be_function_pointer): New function.
* powerpc.cc (Scan::local_reloc_may_be_function_pointer): New function.
(Scan::global_reloc_may_be_function_pointer): New function.
* i386.cc (Scan::local_reloc_may_be_function_pointer): New function.
(Scan::global_reloc_may_be_function_pointer): New function.
* x86_64.cc (Scan::local_reloc_may_be_function_pointer): New function.
(Scan::global_reloc_may_be_function_pointer): New function.
(Scan::possible_function_pointer_reloc): New function.
(Target_x86_64::can_check_for_function_pointers): New function.
* gc.h (gc_process_relocs): Scan relocation types to determine if
function pointers were taken for targets that support it.
* icf.cc (Icf::find_identical_sections): Include functions for
folding in safe ICF whose pointer is not taken.
* icf.h (Secn_fptr_taken_set): New typedef.
(fptr_section_id_): New member.
(section_has_function_pointers): New function.
(set_section_has_function_pointers): New function.
(check_section_for_function_pointers): New function.
* options.h: Fix comment for safe ICF option.
* target.h (can_check_for_function_pointers): New function.
* testsuite/Makefile.am: Add icf_safe_so_test test case.
Modify icf_safe_test for X86-64.
* testsuite/Makefile.in: Regenerate.
* testsuite/icf_safe_so_test.cc: New file.
* testsuite/icf_safe_so_test.sh: New file.
* testsuite/icf_safe_test.cc (kept_func_3): New function.
(main): Change to take pointer to function kept_func_3.
* testsuite/icf_safe_test.sh (arch_specific_safe_fold): Check if safe
folding is done correctly for X86-64.