stubdom: Fix newlib build with GCC-14

Based on a fix from OpenSUSE, but adjusted to be Clang-compatible too.  Pass
-Wno-implicit-function-declaration library-wide rather than using local GCC
pragmas.

Fix of copy_past_newline() to avoid triggering -Wstrict-prototypes.

Link: https://build.opensuse.org/request/show/1178775
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
master commit: 444cb9350f
master date: 2024-10-03 10:07:25 +0100

stubdom/Makefile

@@ -97,10 +97,12 @@ newlib-$(NEWLIB_VERSION): newlib-$(NEWLIB_VERSION).tar.gz
 	patch -d $@ -p1 < newlib-disable-texinfo.patch
 	patch -d $@ -p1 < newlib-cygmon-gmon.patch
 	patch -d $@ -p1 < newlib-makedoc.patch
+	patch -d $@ -p1 < newlib-fix-copy_past_newline.patch
 	find $@ -type f | xargs perl -i.bak \
 		-pe 's/\b_(tzname|daylight|timezone)\b/$$1/g'
 	touch $@
 
+NEWLIB_CFLAGS += -Wno-implicit-function-declaration
 NEWLIB_STAMPFILE=$(CROSS_ROOT)/$(GNU_TARGET_ARCH)-xen-elf/lib/libc.a
 .PHONY: cross-newlib
 cross-newlib: $(NEWLIB_STAMPFILE)

stubdom/newlib-fix-copy_past_newline.patch

@@ -0,0 +1,10 @@
+--- newlib-1.16.0/newlib/doc/makedoc.c.orig
++++ newlib-1.16.0/newlib/doc/makedoc.c
+@@ -798,6 +798,7 @@ DEFUN( iscommand,(ptr, idx),
+ }
+
+
++static unsigned int
+ DEFUN(copy_past_newline,(ptr, idx, dst),
+       string_type *ptr AND
+       unsigned int idx AND