BUG#20013 No pentium_cflags in SETUP.sh

```yaml
Merge pippilotta.erinye.com:/shared/home/df/mysql/build/mysql-5.1-build-work-20013
into  pippilotta.erinye.com:/shared/home/df/mysql/build/mysql-5.1-build
```

reorder lines from BUG#20013 to resemble order in 5.0 


BUILD/SETUP.sh:
  BUG#20013 No pentium_cflags in SETUP.sh
  ---
  reorder lines from BUG#20013 to resemble order in 5.0

BUILD/SETUP.sh

@@ -172,6 +172,7 @@ max_configs="$SSL_LIBRARY --with-plugins=max --with-embedded-server"
 alpha_cflags="$check_cpu_cflags -Wa,-m$cpu_flag"
 amd64_cflags="$check_cpu_cflags"
 amd64_cxxflags=""  # If dropping '--with-big-tables', add here  "-DBIG_TABLES"
+pentium_cflags="$check_cpu_cflags"
 pentium64_cflags="$check_cpu_cflags -m64"
 ppc_cflags="$check_cpu_cflags"
 sparc_cflags=""