ipa-sra: Fix address escape case when detecting Fortran descriptors

ipa-sra: Fix address escape case when detecting Fortran descriptors

The discussion about scan_expr_access in ipa-sra.cc brought my
attention to a missing case of handling an ADDR_EXPR.  As the added
testcase shows, the heuristics which looks for parameters which are
local variables that are only written to and passed by reference in
calls can miss a case where the address of the variable in question is
stored elsewhere in an assignment.

This patch adds that case to the function and also adds the
optimization that Richi suggested, i.e. bailing out early on simple
SSA_NAMEs and constant trees.

gcc/ChangeLog:

2022-12-14  Martin Jambor  <mjambor@suse.cz>

	* ipa-sra.cc (loaded_decls): Adjust comment.
	(scan_expr_access): Also detect assignments of address of local
	variables to a variable.  Bail out early on SSA_NAMEs and
	constants as an optimization.

gcc/testsuite/ChangeLog:

2022-12-14  Martin Jambor  <mjambor@suse.cz>

	* gcc.dg/ipa/ipa-sra-29.c: New test.