libffi: Fix 32-bit SPARC structure passing [PR115681]

libffi: Fix 32-bit SPARC structure passing [PR115681]

The libffi.closures/single_entry_structs2.c test FAILs on 32-bit SPARC:

FAIL: libffi.closures/single_entry_structs2.c -W -Wall -Wno-psabi -O0
execution test

The issue has been reported, analyzed and fixed upstream:

	Several tests FAIL on 32-bit Solaris/SPARC
	https://github.com/libffi/libffi/issues/841

Therefore this patch imports the fix into the GCC tree.

Tested on sparc-sun-solaris2.11.

2024-07-01  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	libffi:
	PR libffi/115681
	* src/sparc/ffi.c (ffi_call_int): Copy structure arguments to
	maintain call-by-value semantics.