ACPICA: acpi_resource_irq: Replace 1-element arrays with flexible array

ACPICA: acpi_resource_irq: Replace 1-element arrays with flexible array

ACPICA commit bfdd3446e7caf795c85c70326c137023942972c5

Similar to "Replace one-element array with flexible-array", replace the
1-element array with a proper flexible array member as defined by C99.

This allows the code to operate without tripping compile-time and run-
time bounds checkers (e.g. via __builtin_object_size(), -fsanitize=bounds,
and/or -fstrict-flex-arrays=3). Note that the spec requires there be at
least one interrupt, so use a union to keep space allocated for this.

The only binary change in .text and .data sections is some rearrangement
by the compiler of acpi_dm_address_common(), but appears to be harmless.

Link: https://github.com/acpica/acpica/commit/bfdd3446
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>