Get rid of Java .jcr section when not using Java

[Johannes Bauer]

Hi there,

I'm using gcc-6.3.0 with the arm-non-eabi target and cross compile for
ARM Cortex-M4. I've just traced an annoyingly elusive issue which
ultimately turned out to be caused by a .jcr section that originates
from gccs CRT. Note that I'm compiling bare metal Cortex-M, so I'm a
million miles away from anything Javaish. There should not be a
Java-related section consuming RAM on my microcontroller, in my opinion.

When I turn on section garbage collection, it goes away (never
referenced, obviously) but in this particular instance, I cannot turn on
section GC. When I try to discard the section via my linker script, I
get complaints:

`.jcr' referenced in section `.text' of
/home/joe/bin/gcc-cm4/lib/gcc/arm-none-eabi/6.3.0/crtbegin.o: defined in
discarded section `.jcr' of
/home/joe/bin/gcc-cm4/lib/gcc/arm-none-eabi/6.3.0/crtbegin.o
collect2: error: ld returned 1 exit status

I'm not the first to encounter this issue, but it doesn't seem to cause
a problem for most people. E.g., I've found this here:

https://gcc.gnu.org/ml/gcc-patches/2013-10/msg00654.html

But it doesn't really apply to fixing this.

Since I do bake my own gcc flavor, I would also be happy with a solution
that'd involve patching around gcc guts, but I'm just too clueless to
know what to touch there.

Any help greatly appreciated,
Thanks,
Johannes