Comment 57 for bug 1752437

drivers/acpi/irq.o: In function `acpi_gsi_to_irq':
irq.c:(.text+0x0): multiple definition of `acpi_gsi_to_irq'
arch/x86/kernel/acpi/boot.o:boot.c:(.text+0x1a0): first defined here
drivers/acpi/irq.o: In function `acpi_register_gsi':
irq.c:(.text+0x70): multiple definition of `acpi_register_gsi'
arch/x86/kernel/acpi/boot.o:boot.c:(.text+0x0): first defined here
drivers/acpi/irq.o: In function `acpi_unregister_gsi':
irq.c:(.text+0xf0): multiple definition of `acpi_unregister_gsi'
arch/x86/kernel/acpi/boot.o:boot.c:(.text+0x10): first defined here
drivers/acpi/irq.o:(.bss+0x0): multiple definition of `acpi_irq_model'
arch/x86/kernel/acpi/boot.o:(.bss+0x8): first defined here
make: *** [Makefile:1010: vmlinux] Error 1

After applying the patch I get the above on 4.18.5