scripts: Rework the approach for building older kernels with a recent gcc

Instead of setting KCFLAGS, modify include/linux/compiler-gcc.h.


git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@9003 d57e44dd-8a1f-0410-8b47-8ef2f437770f

scripts/run-regression-tests

@@ -695,15 +695,6 @@ do
     run_checkpatch "$k"
   fi
   patch_and_configure_kernel "$k" || continue
-  case "$k" in
-      *^*)
-	  # CentOS.
-	  ;;
-      2.*|3.*)
-	  # Tell the kernel that we are using gcc 4.6 since older kernel
-	  # versions do not suppor recent gcc versions.
-	  KCFLAGS="-U__GNUC__ -U__GNUC_MINOR__ -D__GNUC__=4 -D__GNUC_MINOR__=6"
-  esac
   case "$k" in
       3.10.0-*)
 	  # Make the CentOS 7.x build less noisy.