GhcWithNativeCodeGen=NO for Sparc, until the old Sparc native codegen
is updated (not likely to happen soon).
# (as well as a C backend)
#
# Target platforms supported:
-# i386, sparc & powerpc
-ifneq "$(findstring $(HostArch_CPP), i386 sparc powerpc)" ""
+# i386, powerpc
+# sparc has bitrotted
+ifneq "$(findstring $(HostArch_CPP), i386 powerpc)" ""
GhcWithNativeCodeGen=YES
else
GhcWithNativeCodeGen=NO