BUILD: Makefile: Disable -Wcast-function-type if it exists.
Disable -Wcast-function-type for recent gcc, if we're casting a function
type to another one, it is assumed we know what we're doing.
diff --git a/Makefile b/Makefile
index 6d7a015..f28ed58 100644
--- a/Makefile
+++ b/Makefile
@@ -186,6 +186,7 @@
SPEC_CFLAGS += $(call cc-nowarn,missing-field-initializers)
SPEC_CFLAGS += $(call cc-nowarn,implicit-fallthrough)
SPEC_CFLAGS += $(call cc-nowarn,stringop-overflow)
+SPEC_CFLAGS += $(call cc-nowarn,cast-function-type)
SPEC_CFLAGS += $(call cc-opt,-Wtype-limits)
SPEC_CFLAGS += $(call cc-opt,-Wshift-negative-value)
SPEC_CFLAGS += $(call cc-opt,-Wshift-overflow=2)