rts: configure.ac should populate HAVE_LIBNUMA instead of USE_LIBNUMA
rts: configure.ac should populate HAVE_LIBNUMA instead of USE_LIBNUMA

Code in rts/ which deals with numa checks for `#if HAVE_LIBNUMA`,
however this macro is not populated during `./configure`.
https://phabricator.haskell.org/D2329 changed this code last and we
instead set `USE_LIBNUMA` which fails to setup numa correctly.

Test Plan:
From main directory in ghc,

  ./configure && make clean && make boot && make
  cd nofib/parallel/queens
  ../../../inplace/bin/ghc-stage2 Main.hs -rtsopts -threaded
  ./Main 15 +RTS -N24 -s -A64m --numa

This fails before this patch with

  Main: --numa: OS reports NUMA is not available

After the fix, it works as expected.

Run the validation script,

  ./validate

(It fails with an error in `compiler/utils/Util.hs` saying
`GHC.Stack.CallStack` not found, once I remove this 1 line from this
file , the script works)

Reviewers: hvr, austin, bgamari, erikd, simonmar

Reviewed By: erikd, simonmar

Subscribers: mpickering, thomie, erikd, niteria

Differential Revision: https://phabricator.haskell.org/D2620

GHC Trac Issues: #12741

shlevy/ghc,ezyang/ghc,sdiehl/ghc,shlevy/ghc,ezyang/ghc,ezyang/ghc,shlevy/ghc,sdiehl/ghc,mettekou/ghc,shlevy/ghc,olsner/ghc,shlevy/ghc,mettekou/ghc,olsner/ghc,mettekou/ghc,mettekou/ghc,mettekou/ghc,sdiehl/ghc,ezyang/ghc,olsner/ghc,ezyang/ghc,mettekou/ghc,ezyang/ghc,sdiehl/ghc,olsner/ghc,olsner/ghc,olsner/ghc,shlevy/ghc,sdiehl/ghc,ezyang/ghc,olsner/ghc,shlevy/ghc,mettekou/ghc,sdiehl/ghc,sdiehl/ghc