compiling newlib

[Paul Zimmermann]

       Dear Christophe,

> + #include <errno.h>
> probably would have avoided the trouble to add newlib-specific code.

of course I tried, but I get with #include <errno.h>:

$ gcc e.c /localdisk/zimmerma/newlib/libm/libm.a
/usr/bin/ld: /localdisk/zimmerma/newlib/libm/libm.a(lib_a-k_standard.o): in function `__kernel_standard':
k_standard.c:(.text+0x39): undefined reference to `__errno'
/usr/bin/ld: k_standard.c:(.text+0x59): undefined reference to `__errno'
/usr/bin/ld: k_standard.c:(.text+0x7f): undefined reference to `__errno'
/usr/bin/ld: k_standard.c:(.text+0xa1): undefined reference to `__errno'
/usr/bin/ld: k_standard.c:(.text+0xc1): undefined reference to `__errno'
/usr/bin/ld: /localdisk/zimmerma/newlib/libm/libm.a(lib_a-k_standard.o):k_standard.c:(.text+0xe9): more undefined references to `__errno' follow
collect2: error: ld returned 1 exit status

Best regards,
Paul

PS: I discovered that while comparing different libraries for single-precision
functions: <https://members.loria.fr/PZimmermann/papers/accuracy.pdf>