ipa: Teach IPA-CP transformation about IPA-SRA modifications (PR 103227)

PR 103227 exposed an issue with ordering of transformations of IPA
passes.  IPA-CP can create clones for constants passed by reference
and at the same time IPA-SRA can also decide that the parameter does
not need to be a pointer (or an aggregate) and plan to convert it
into (a) simple scalar(s).  Because no intermediate clone is created
just for the purpose of ordering the transformations and because
IPA-SRA transformation is implemented as part of clone
materialization, the IPA-CP transformation happens only afterwards,
reversing the order of the transformations compared to the ordering of
analyses.

IPA-CP transformation looks at planned substitutions for values passed
by reference or in aggregates but finds that all the relevant
parameters no longer exist.  Currently it subsequently simply gives
up, leading to clones created for no good purpose (and huge regression
of 548.exchange_r.  This patch teaches it recognize the situation,
look up the new scalarized parameter and perform value substitution on
it.  On my desktop this has recovered the lost exchange2 run-time (and
some more).

I have disabled IPA-SRA in a Fortran testcase so that the dumping from
the transformation phase can still be matched in order to verify that
IPA-CP understands the IL after verifying that it does the right thing
also with IPA-SRA.

gcc/ChangeLog:

2021-11-23  Martin Jambor  <mjambor@suse.cz>

	PR ipa/103227
	* ipa-prop.h (ipa_get_param): New overload.  Move bits of the existing
	one to the new one.
	* ipa-param-manipulation.h (ipa_param_adjustments): New member
	function get_updated_index_or_split.
	* ipa-param-manipulation.c
	(ipa_param_adjustments::get_updated_index_or_split): New function.
	* ipa-prop.c (adjust_agg_replacement_values): Reimplement, add
	capability to identify scalarized parameters and perform substitution
	on them.
	(ipcp_transform_function): Create descriptors earlier, handle new
	return values of adjust_agg_replacement_values.

gcc/testsuite/ChangeLog:

2021-11-23  Martin Jambor  <mjambor@suse.cz>

	PR ipa/103227
	* gcc.dg/ipa/pr103227-1.c: New test.
	* gcc.dg/ipa/pr103227-3.c: Likewise.
	* gcc.dg/ipa/pr103227-2.c: Likewise.
	* gfortran.dg/pr53787.f90: Disable IPA-SRA.

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