[i386] restore recompute to override opts after change [PR113719]

The first patch for PR113719 regressed gcc.dg/ipa/iinline-attr.c on
toolchains configured to --enable-frame-pointer, because the
optimization node created within handle_optimize_attribute had
flag_omit_frame_pointer incorrectly set, whereas
default_optimization_node didn't.  With this difference,
can_inline_edge_by_limits_p flagged an optimization mismatch and we
refused to inline the function that had a redundant optimization flag
into one that didn't, which is exactly what is tested for there.

This patch restores the calls to ix86_default_align and
ix86_recompute_optlev_based_flags that used to be, and ought to be,
issued during TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE, but preserves the
intent of the original change, of having those functions called at
different spots within ix86_option_override_internal.  To that end,
the remaining bits were refactored into a separate function, that was
in turn adjusted to operate on explicitly-passed opts and opts_set,
rather than going for their global counterparts.


for  gcc/ChangeLog

	PR target/113719
	* config/i386/i386-options.cc
	(ix86_override_options_after_change_1): Add opts and opts_set
	parms, operate on them, after factoring out of...
	(ix86_override_options_after_change): ... this.  Restore calls
	of ix86_default_align and ix86_recompute_optlev_based_flags.
	(ix86_option_override_internal): Call the factored-out bits.