common.opt and optimization attribute housekeeping

Hi,
this patch finishes transition of IPA passes to be per-function (and thus behaving sanely
at LTO time when different flags are mixed).
It also goes through common.opt and fixes attributes of quite few flags:

	fauto-inc-dec, fdelete-dead-exceptions, ffunction-cse,
	fgraphite, fstrict-volatile-bitfields, fira-algorithm, fira-region,
	fira-share-save-slots, fira-share-spill-slots,
	fmodulo-sched-allow-regmoves, fpartial-inlining,
	sched-stalled-insns, fsched-stalled-insns-dep, fstrict-overflow,
	ftracer, ftree-parallelize-loops, fassociative-math,
	freciprocal-math, fvect-cost-model, fsimd-cost-model, flag_stack_reuse

are all function local properties and thus should be marked as Optimization.
while

	fauto-profile, fcommon, fdata-sections, fipa-icf-variables,
        ftoplevel-reorder, funit-at-a-time, fwhole-program

currentwly won't work in optimization attributes (and won't get properly maintained
to LTO). This is becuase either they affect variables that are not annotated or because
they are decided globally for whole compilation unit.

There are few cases I need to look into still:

flag-function-sections
  - Here we can support optimizaiton attribute but currently don't - basically it
    needs revisiting the few flag_function_sections uses and making the opt_for_fn.
flag_gnu_tm
flag_gnu_unique
  - Those probably can be turned into Optimization but I have no clue.
flag_proflie_reorder_functions
  - can be handled but isn't at the moment.        
flag_split_stack
  - this one needs some unit finalization
flag_stack_protector
  - Probably can be supported as Optimization
flag_strict_aliasing
  - This is marked as Optimization, but I blieve it does not work that way because
    alias classes are assigned to types that gets shared.  It would be great to support
    this since a lot of real code is mixing the settings.
flag_toplevel_reorder
  - This can be supported but isn't
    Similarly to flag_proflie_reorder_functions needs a bit tweaking of lto and cgraphunit.
fp_contract_mode
  - This probalby should be optimization but doing so makes the awk machinery to fail.

Bootstrapped/regtested x86_64-linux, will commit it later today if there are no complains.

Honza

	* ipa-reference.c (set_reference_optimization_summary,
	ipa_reference_get_not_written_global): Do nothing if ipa-reference is disabled.
	(propagate_bits): If ipa-reference is disabled, do not look into local properties.
	(analyze_function): Disable analysis when ipa_reference is disabled.
	(generate_summary): Do not dump when reference is disabled.
	(get_read_write_all_from_node): When ipa-reference is disabled, use the
	node flags.
	(gate): Enable for LTO.
	* optc-save-gen.awk: Handle optimize_debug correctly.
	* opth-gen.awk: Likewise.
	* common.opt (fauto-inc-dec, fdelete-dead-exceptions, ffunction-cse,
	fgraphite, fstrict-volatile-bitfields, fira-algorithm, fira-region,
	fira-share-save-slots, fira-share-spill-slots,
	fmodulo-sched-allow-regmoves, fpartial-inlining,
	sched-stalled-insns, fsched-stalled-insns-dep, fstrict-overflow,
	ftracer, ftree-parallelize-loops, fassociative-math,
	freciprocal-math, fvect-cost-model, fsimd-cost-model): Mark as
	Optimization
	(fauto-profile, fcommon, fdata-sections, fipa-icf-variables,
        ftoplevel-reorder, funit-at-a-time, fwhole-program): Do not mark as
        Optimization.
	* ipa-icf.c (gate, sem_item_optimizer::filter_removed_items):
	Fix for IPA.

common.opt and optimization attribute housekeeping

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Patch