issues on gcc202

[paul zimmermann]

I find several issues on gcc202.fsffrance.org:

1) gmp-6.1.2 configured with --disable-shared and gcc 7.2.0: libgmp.a
   contains an undefined symbol __gmpn_addlsh1_n_ip1:
   zimmerma at gcc202:/tmp/gmp-6.1.2$ cat e.c
   #include "gmp.h"
   int main()
   {
     mpz_t x;
     mpz_init_set_str (x, "1234567890", 10);
     mpz_sqrt (x, x);
   }
   zimmerma at gcc202:/tmp/gmp-6.1.2$ gcc -I/tmp/include e.c /tmp/lib/libgmp.a
   /tmp/lib/libgmp.a(lt86-sqrtrem.o): In function `mpn_dc_sqrtrem':
   sqrtrem.c:(.text+0x4b8): undefined reference to `__gmpn_addlsh1_n_ip1'
   /tmp/lib/libgmp.a(lt86-sqrtrem.o): In function `mpn_dc_sqrt':
   sqrtrem.c:(.text+0xa1c): undefined reference to `__gmpn_addlsh1_n_ip1'
   collect2: error: ld returned 1 exit status

2) still with the same configuration, t-constants fails:
   zimmerma at gcc202:/tmp/gmp-6.1.2$ tests/t-constants 
   PP_INVERTED == 21cfe6cfc938b36b, but pp_inverted_calc == 1dde20a605db167d
   ...

With the latest snapshot (gmp-6.1.99-20170829), issue 1) is fixed, but not
issue 2).

Paul