gmp-6.1.2: configure MPN_PATH="generic" fails on 64 bit

[Torbjörn Granlund]

Karsten Scheibler <karsten.scheibler at btc-es.de> writes:

  Compiling gmp-6.1.2 on Ubuntu 16.04.4 (x86_64) with a ./configure
  works without problems.
  But when trying to disable the assembly routines using:

  ./configure MPN_PATH="generic"

  configure fails with the following error:

  configure: error: no version of invert_limb_table found in path: generic

  In contrast, when using 32 bit configure has no problems (make
  finishes without problems as well):

  ./configure ABI=32 MPN_PATH="generic" CFLAGS="-m32"

  Furthermore, gmp-6.1.99-20180418 behaves the same.

Playing with GMP's various internal variables (be it configure, make, or
library variables) is strongly discouraged.  Please use the documented
methods for configuration, build and use of GMP.

-- 
Torbjörn
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