Re: GNU make 3.81 with GCC 14

Kia ora koutou,
Prompted by Greg's discussion of flags to adjust C compiler behaviour I
decided to see if the GCC 14 release notes had anything to say on this
matter.

And they do. The release notes link to
https://gcc.gnu.org/gcc-14/porting_to.html which says old code that
can't be fixed "can be compiled with -fpermissive, -std=gnu89, or -
std=c89". 

I tried "-std=c89" because that looked like it would be more likely to
work on other compilers, but GNU make 3.81 uses extensions to the C
language. I tried "-std=gnu89" and that worked fine.

I've just looked through the tools Makefiles and I can see that we
already have a mechanism to detect GCC versions for this sort of job.

Does the following look like a good idea to add to
tools/gmake/Makefile? I can create a PR for it easily enough.

	.if ${HAVE_GCC} > 13
	HOST_CFLAGS+=		-std=gnu89
	.endif

Ngā mihi,
Lloyd