Serialization dependencies muck up configure-on-demand

[Nathanael Nerode]

Daniel mentioned:
>However, GNU make has the answer.  We'd probably have to autoconf for
>this feature, it's quite new:
>    * A new feature exists: order-only prerequisites.  These 
>prerequisites
>      affect the order in which targets are built, but they do not 
>impact
>      the rebuild/no-rebuild decision of their dependents.  That is to 
>say,
>      they allow you to require target B be built before target A, 
>without
>      requiring that target A will always be rebuilt if target B is 
>updated.
>      Patch for this feature provided by Greg McGary <greg@mcgary.org>.
>
>The syntax is:
>TARGETS : NORMAL-PREREQUISITES | ORDER-ONLY-PREREQUISITES
>
>So if that works in a test at autoconf time, we could use it.

Quite right; if configure detects that this is available, we should use 
this in the Makefile rather than the existing scheme.

Unfortuntately, I'm not feeling up to coding this for a while. :-(

Would there be interest in temporarily disabling the serialization 
dependencies (since .NOTPARALLEL is still there) until we can get a 
better solution for all this?  I'm just thinking of 
"if (0)"ing them out in 'configure.in' for the time being.

--Nathanael