UNREG: fix implicit declarations from pdep and pext

Authored by trofi on Mar 9 2018, 11:43 AM.

Description

UNREG: fix implicit declarations from pdep and pext

Unreg build failed as:

$ ./configure --enable-unregisterised
$ make

HC [stage 1] libraries/ghc-prim/dist-install/build/GHC/PrimopWrappers.o
  ghc_1.hc: In function 'ghczmprim_GHCziPrimopWrappers_pdep8zh_entry':

  ghc_1.hc:1810:9: error:
   error: implicit declaration of function 'hs_pdep8'; did you mean 'hs_ctz8'?
     [-Werror=implicit-function-declaration]
   _c3jz = hs_pdep8(*Sp, Sp[1]);
           ^~~~~~~~
           hs_ctz8
     |
1810 | _c3jz = hs_pdep8(*Sp, Sp[1]);
     |         ^

Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>