patches: add coreboot toolchain 4.16 compatibility

Warnings stuff, Ada stuff, etc.

src/coreboot/default.nix

@@ -124,6 +124,7 @@ stdenv.mkDerivation {
     ./patches/0018-use_fallback-rk3399-gru-kevin-use-fallback-if-watchd.patch
     ./patches/0019-use_fallback-rk3399-gru-kevin-update-for-coreboot-4..patch
     ./patches/0020-use_fallback-kgpe-d16-implement-using-nvram-with-cmo.patch
+    ./patches/0027-coreboot-toolchain-4_16_compat.patch
   ];
 
   postPatch = ''

src/coreboot/patches/0027-coreboot-toolchain-4_16_compat.patch

@@ -0,0 +1,22 @@
+diff --git c/Makefile.inc i/Makefile.inc
+index b25ac6b426..73df96d31c 100644
+--- c/Makefile.inc
++++ i/Makefile.inc
+@@ -439,14 +439,14 @@ ADAFLAGS_common += -ffunction-sections -fdata-sections
+ # .Y   Disable information messages for why package spec needs body:
+ #      Those messages are annoying. But don't forget to enable those,
+ #      if you need the information.
+-ADAFLAGS_common += -gnatwa.eeD.HHTU.U.W.Y
++ADAFLAGS_common += -gnatwa.eeD.HHTU.U.W.Y -gnatwR
+ # Disable style checks for now
+ ADAFLAGS_common += -gnatyN
+
+-LDFLAGS_common := --gc-sections -nostdlib -nostartfiles -static --emit-relocs
++LDFLAGS_common := --gc-sections -nostdlib --nmagic -static --emit-relocs
+
+ ifeq ($(CONFIG_WARNINGS_ARE_ERRORS),y)
+-CFLAGS_common += -Werror
++CFLAGS_common += -Werror -Wno-address-of-packed-member
+ endif
+ ifneq ($(GDB_DEBUG),)
+ CFLAGS_common += -Og