Remove pstack from default build (because conflict with mit-pthreads)

configure.in:
  Don't enable pstack if mit-pthreads

Build-tools/Do-all-build-steps

@@ -65,7 +65,7 @@ aclocal; autoheader; aclocal; automake; autoconf
  --enable-thread-safe-client \
  --with-berkeley-db \
  --with-innodb \
- --with-pstack \
+ --without-pstack \
  --with-extra-tools \
  --with-embedded-server
 

configure.in

@@ -688,7 +688,7 @@ int main()
     [USE_PSTACK=yes])
   pstack_libs=
   pstack_dirs=
-  if test "$USE_PSTACK" = yes -a "$IS_LINUX" = "true" -a "$MACHINE_TYPE" = "i686"
+  if test "$USE_PSTACK" = yes -a "$IS_LINUX" = "true" -a "$MACHINE_TYPE" = "i686" -a "$with_mit_threads" = "no"
   then
     have_libiberty= have_libbfd=
     my_save_LIBS="$LIBS"